PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information.PDF generated at: Thu, 08 Jul 2010 07:03:31 UTC

Human Factors &Ergonomics in Design

ContentsArticles

Human factors 1Ergonomics 14Anthropometry 22Rohmert's law 28Experience design 28Industrial design 30Design for All (design philosophy) 34Human–computer interaction 36Repetitive strain injury 44

ReferencesArticle Sources and Contributors 52Image Sources, Licenses and Contributors 54

Article LicensesLicense 55

Human factors 1

Human factorsHuman factors science or human factors technologies is a multidisciplinary field incorporating contributions frompsychology, engineering, industrial design, statistics, operations research and anthropometry. It is a term that covers:• The science of understanding the properties of human capability (Human Factors Science).• The application of this understanding to the design, development and deployment of systems and services

(Human Factors Engineering).• The art of ensuring successful application of Human Factors Engineering to a program (sometimes referred to as

Human Factors Integration). It can also be called ergonomics.In general, a human factor is a physical or cognitive property of an individual or social behavior which is specific tohumans and influences functioning of technological systems as well as human-environment equilibriums.In social interactions, the use of the term human factor stresses the social properties unique to or characteristic ofhumans.Human factors involves the study of all aspects of the way humans relate to the world around them, with the aim ofimproving operational performance, safety, through life costs and/or adoption through improvement in theexperience of the end user.The terms human factors and ergonomics have only been widely used in recent times; the field's origin is in thedesign and use of aircraft during World War II to improve aviation safety. It was in reference to the psychologistsand physiologists working at that time and the work that they were doing that the terms "applied psychology" and“ergonomics” were first coined. Work by Elias Porter, Ph.D. and others within the RAND Corporation after WWIIextended these concepts. "As the thinking progressed, a new concept developed - that it was possible to view anorganization such as an air-defense, man-machine system as a single organism and that it was possible to study thebehavior of such an organism. It was the climate for a breakthrough."[1]

Specialisations within this field include cognitive ergonomics, usability, human computer/human machineinteraction, and user experience engineering. New terms are being generated all the time. For instance, “user trialengineer” may refer to a human factors professional who specialises in user trials. Although the names change,human factors professionals share an underlying vision that through application of an understanding of humanfactors the design of equipment, systems and working methods will be improved, directly affecting people’s lives forthe better.Human factors practitioners come from a variety of backgrounds, though predominantly they are psychologists(engineering, cognitive, perceptual, and experimental) and physiologists. Designers (industrial, interaction, andgraphic), anthropologists, technical communication scholars and computer scientists also contribute. Though somepractitioners enter the field of human factors from other disciplines, both M.S. and Ph.D. degrees in Human FactorsEngineering are available from several universities worldwide.

The Formal History of American Human Factors EngineeringThe formal history describes activities in known chronological order. This can be divided into 5 markers:• Developments prior to World War I• Developments during World War I• Developments between World War I and World War II• Developments during World War II• Developments after World War II[2] Developments prior to World War I: Prior to WWI the only test of human to machine compatibility was that of

Human factors 2

trial and error. If the human functioned with the machine, he was accepted, if not he was rejected. There was asignificant change in the concern for humans during the American civil war. The US patent office was concernedwhether the mass produced uniforms and new weapons could be used by the infantry men. The next developmentwas when the American inventor Simon Lake tested submarine operators for psychological factors, followed by thescientific study of the worker. This was an effort dedicated to improve the efficiency of humans in the work place.These studies were designed by F W Taylor. The next step was the derivation of formal time and motion study fromthe studies of Frank Gilbreth, Sr. and Lillian Gilbreth. Developments during World War I: With the onset of WWI, more sophisticated equipment was developed. Theinability of the personnel to use such systems led to an increase in interest in human capability. Earlier the focus ofaviation psychology was on the aviator himself. But as time progressed the focus shifted onto the aircraft, inparticular, the design of controls and displays, the effects of altitude and environmental factors on the pilot. The warsaw the emergence of aeromedical research and the need for testing and measurement methods. Still, the war did notcreate a Human Factors Engineering (HFE) discipline, as such. The reasons attributed to this are that technology wasnot very advanced at the time and America's involvement in the war only lasting for 18 months.[2] Developments between World War I and World War II: This period saw relatively slow development in HFE.Although, studies on driver behaviour started gaining momentum during this period, as Henry Ford started providingmillions of Americans with automobiles. Another major development during this period was the performance ofaeromedical research. By the end of WWI, two aeronautical labs were established, one at Brooks Airforce Base,Texas and the other at Wright field outside of Dayton, Ohio. Many tests were conducted to determine whichcharacteristic differentiated the successful pilots from the unsuccessful ones. During the early 1930s, Edwin Linkdeveloped the first flight simulator. The trend continued and more sophisticated simulators and test equipment weredeveloped. Another significant development was in the civilian sector, where the effects of illumination on workerproductivity were examined. This led to the identification of the 'Hawthorne Effect', which suggested thatmotivational factors could significantly influence human performance.[2] Developments during World War II: With the onset of the WW II, it was no longer possible to adopt theTayloristic principle of matching individuals to preexisting jobs. Now the design of equipment had to take intoaccount human limitations and take advantage of human capabilities. This change took time to come into place.There was a lot of research conducted to determine the human capabilities and limitations that had to beaccomplished. A lot of this research took off where the aeromedical research between the wars had left off. Anexample of this is the study done by Fitts and Jones (1947), who studied the most effective configuration of controlknobs to be used in aircraft cockpits. A lot of this research transcended into other equipment with the aim of makingthe controls and displays easier for the operators to use. After the war, the Army Air Force published 19 volumessummarizing what had been established from research during the war.[2] Developments after World War II: In the initial 20 years after the WW II, most activities were done by thefounding fathers: Alphonse Chapanis, Paul Fitts, and Small. The beginning of cold war led to a major expansion ofDefense supported research laboratories. Also, a lot of labs established during the war started expanding. Most of theresearch following the war was military sponsored. Large sums of money were granted to universities to conductresearch. The scope of the research also broadened from small equipments to entire workstations and systems.Concurrently, a lot of opportunities started opening up in the civilian industry. The focus shifted from research toparticipation through advice to engineers in the design of equipment. After 1965, the period saw a maturation of thediscipline. The field has expanded with the development of the computer and computer applications.[2]

Human factors 3

The Cycle of Human FactorsHuman Factors involves the study of factors and development of tools that facilitate the achievement of these goals.In the most general sense, the three goals of human factors are accomplished through several procedures in thehuman factors cycle, which depicts the human operator (brain and body) and the system with which he or she isinteracting. First it is necessary to diagnose or identify the problems and deficiencies in the human-systeminteraction of an existing system. After defining the problems there are five different approaches that can be used inorder to implement the solution. These are as follows:• Equipment Design: changes the nature of the physical equipment with which humans work.• Task Design: focuses more on changing what operators do than on changing the devices they use. This may

involve assigning part or all of tasks to other workers or to automated components.• Environmental Design: implements changes, such as improved lighting, temperature control and reduced noise in

the physical environment where the task is carried out.• Training the individuals: better preparing the worker for the conditions that he or she will encounter in the job

environment by teaching and practicing the necessary physical or mental skills.• Selection of individuals: is a technique that recognizes the individual differences across humans in every physical

and mental dimension that is relevant for good system performance. Such a performance can be optimized byselecting operators who possess the best profile of characteristics for the job.

Human Factors ScienceHuman factors are sets of human-specific physical, cognitive, or social properties which either may interact in acritical or dangerous manner with technological systems, the human natural environment, or human organizations, orthey can be taken under consideration in the design of ergonomic human-user oriented equipment. The choice oridentification of human factors usually depends on their possible negative or positive impact on the functioning ofhuman-organizations and human-machine systems.

The human-machine modelsee also: human-machine systemThe simple human-machine model is a person interacting with a machine in some kind of environment. The personand machine are both modeled as information-processing devices, each with inputs, central processing, and outputs.The inputs of a person are the senses (e.g., eyes, ears) and the outputs are effectors (e.g., hands, voice). The inputs ofa machine are input control devices (e.g., keyboard, mouse) and the outputs are output display devices (e.g., screen,auditory alerts). The environment can be characterized physically (e.g., vibration, noise, zero-gravity), cognitively(e.g., time pressure, uncertainty, risk), and/or organizationally (e.g., organizational structure, job design). Thisprovides a convenient way for organizing some of the major concerns of human engineering: the selection anddesign of machine displays and controls; the layout and design of workplaces; design for maintainability; and thedesign of the work environment.Example: Driving an automobile is a familiar example of a simple man-machine system. In driving, the operatorreceives inputs from outside the vehicle (sounds and visual cues from traffic, obstructions, and signals) and fromdisplays inside the vehicle (such as the speedometer, fuel indicator, and temperature gauge). The driver continuallyevaluates this information, decides on courses of action, and translates those decisions into actions upon the vehicle'scontrols—principally the accelerator, steering wheel, and brake. Finally, the driver is influenced by suchenvironmental factors as noise, fumes, and temperature.No matter how important it may be to match an individual operator to a machine, some of the most challenging andcomplex human problems arise in the design of large man-machine systems and in the integration of humanoperators into these systems. Examples of such large systems are a modern jet airliner, an automated post office, an

Human factors 4

industrial plant, a nuclear submarine, and a space vehicle launch and recovery system. In the design of such systems,human-factors engineers study, in addition to all the considerations previously mentioned, three factors: personnel,training, and operating procedures.• Personnel are trained; that is, they are given appropriate information and skills required to operate and maintain thesystem. System design includes the development of training techniques and programs and often extends to the designof training devices and training aids.• Instructions, operating procedures, and rules set forth the duties of each operator in a system and specify how thesystem is to function. Tailoring operating rules to the requirements of the system and the people in it contributesgreatly to safe, orderly, and efficient operations.

Human Factors EngineeringHuman Factors Engineering (HFE) is the discipline of applying what is known about human capabilities andlimitations to the design of products, processes, systems, and work environments. It can be applied to the design ofall systems having a human interface, including hardware and software. Its application to system design improvesease of use, system performance and reliability, and user satisfaction, while reducing operational errors, operatorstress, training requirements, user fatigue, and product liability. HFE is distinctive in being the only discipline thatrelates humans to technology.Human factors engineering focuses on how people interact with tasks, machines (or computers), and the environmentwith the consideration that humans have limitations and capabilities. Human factors engineers evaluate "Human toHuman," "Human to Group," "Human to Organizational," and "Human to Machine (Computers)" interactions tobetter understand these interactions and to develop a framework for evaluation.Human Factors engineering activities include: 1. Usability assurance 2. Determination of desired user profiles 3.Development of user documentation 4. Development of training programs.

Usability assuranceUsability assurance is an interdisciplinary concept, integrating system engineering with Human Factors engineeringmethodologies. Usability assurance is achieved through the system or service design, development, evaluation anddeployment.• User interface design comprises physical (ergonomic) design, interaction design and layout design.• Usability development comprises integration of human factors in project planning and management, including

system specification documents: requirements, design and testing.• Usability evaluation is a continuous process, starting with the operational requirements specification, through

prototypes of the user interfaces, through usability alpha and beta testing, and through manual and automatedfeedback after the system has been deployed.

Human factors 5

User Interface Design

Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactivecomputing systems for human use and with the study of major phenomena surrounding them. This is a well knownsubject of Human Factors within the Engineering field. There are many different ways to determine human computerinteraction at the user interface by usability testing.

Human Factors Evaluation Methods

Human Factors evaluation methods are part of Human Factors methodology, which is part of Human FactorsEngineering.Besides evaluation, Human Factors Engineering also deals with methods for usability assurance, for assessingdesired user profiles, for developing user documentation and training programs, etc.Until recently, methods used to evaluate human factors ranged from simple questionnaires to more complex andexpensive usability labs[3] .Recently, new methods were proposed, based on analysis of logs of the activity of the system users.Actually, the work in usability labs and that of the new methods is part of Usability Engineering, which is part ofHuman Factors Engineering.

Brief Summary of Human Factors Evaluation Methods

Ethnographic analysis: Using methods derived from ethnography, this process focuses on observing the uses oftechnology in a practical environment. It is a qualitative and observational method that focuses on "real-world"experience and pressures, and the usage of technology or environments in the workplace. The process is best usedearly in the design process.[4]

Focus Groups: Focus groups are another form of qualitative research in which one individual will facilitatediscussion and elicit opinions about the technology or process under investigation. This can be on a one to oneinterview basis, or in a group session. Can be used to gain a large quantity of deep qualitative data,[5] though due tothe small sample size, can be subject to a higher degree of individual bias.[6] Can be used at any point in the designprocess, as it is largely dependent on the exact questions to be pursued, and the structure of the group. Can beextremely costly.Iterative design: Also known as prototyping, the iterative design process seeks to involve users at several stages ofdesign, in order to correct problems as they emerge. As prototypes emerge from the design process, these aresubjected to other forms of analysis as outlined in this article, and the results are then taken and incorporated into thenew design. Trends amongst users are analyzed, and products redesigned. This can become a costly process, andneeds to be done as soon as possible in the design process before designs become too concrete.[4]

Meta-analysis: A supplementary technique used to examine a wide body of already existing data or literature in orderto derive trends or form hypotheses in order to aid design decisions. As part of a literature survey, a meta-analysiscan be performed in order to discern a collective trend from individual variables.[6]

Subjects-in-tandem: Two subjects are asked to work concurrently on a series of tasks while vocalizing theiranalytical observations. This is observed by the researcher, and can be used to discover usability difficulties. Thisprocess is usually recorded.Surveys and Questionnaires: A commonly used technique outside of Human Factors as well, surveys andquestionnaires have an advantage in that they can be administered to a large group of people for relatively low cost,enabling the researcher to gain a large amount of data. The validity of the data obtained is, however, always inquestion, as the questions must be written and interpreted correctly, and are, by definition, subjective. Those whoactually respond are in effect self-selecting as well, widening the gap between the sample and the populationfurther.[6]

Human factors 6

Task analysis: A process with roots in activity theory, task analysis is a way of systematically describing humaninteraction with a system or process to understand how to match the demands of the system or process to humancapabilities. The complexity of this process is generally proportional to the complexity of the task being analyzed,and so can vary in cost and time involvement. It is a qualitative and observational process. Best used early in thedesign process.[6]

Think aloud protocol: Also known as "concurrent verbal protocol", this is the process of asking a user to execute aseries of tasks or use technology, while continuously verbalizing their thoughts so that a researcher can gain insightsas to the users' analytical process. Can be useful for finding design flaws that do not affect task performance, butmay have a negative cognitive affect on the user. Also useful for utilizing experts in order to better understandprocedural knowledge of the task in question. Less expensive than focus groups, but tends to be more specific andsubjective.[7]

User analysis: This process is based around designing for the attributes of the intended user or operator, establishingthe characteristics that define them, creating a persona for the user. Best done at the outset of the design process, auser analysis will attempt to predict the most common users, and the characteristics that they would be assumed tohave in common. This can be problematic if the design concept does not match the actual user, or if the identified aretoo vague to make clear design decisions from. This process is, however, usually quite inexpensive, and commonlyused.[6]

"Wizard of Oz": This is a comparatively uncommon technique but has seen some use in mobile devices. Based uponthe Wizard of Oz experiment, this technique involves an operator who remotely controls the operation of a device inorder to imitate the response of an actual computer program. It has the advantage of producing a highly changeableset of reactions, but can be quite costly and difficult to undertake.

Problems with Human Factors Methods

Problems in how usability measures are employed include:(1) measures of learning and retention of how to use an interface are rarely employed during methods and(2) some studies treat measures of how users interact with interfaces as synonymous with quality-in-use, despite anunclear relation.[8]

Weakness of Usability Lab Testing

Although usability lab testing is believed to be the most influential evaluation method, it does have some limitations.These limitations include:(1) Additional resources and time than other methods(2) Usually only examines a fraction of the entire market segment(3) Test scope is limited to the sample tasks chosen(4) Long term ease-of-use problems are difficult to identify(5) May reveal only a fraction of total problems(6) Laboratory setting excludes factors that the operational environment places on the products usability

Weakness of Inspection Methods

Inspection methods (expert reviews and walkthroughs) can be accomplished quickly, without resources from outsidethe development team, and does not require the research expertise that usability tests need. However, inspectionmethods do have limitations, which include:(1) Do not usually directly involve users(2) Often do not involve developers(3) Set up to determine problems and not solutions(4) Do not foster innovation or creative solutions(5) Not good at persuading developers to make product improvements

Human factors 7

Weakness of Surveys, Interviews, and Focus Groups

These traditional human factors methods have been adapted, in many cases, to assess product usability. Even thoughthere are several surveys that are tailored for usability and that have established validity in the field, these methodsdo have some limitations, which include:(1) Reliability of all surveys is low with small sample sizes (10 or less)(2) Interview lengths restricts use to a small sample size(3) Use of focus groups for usability assessment has highly debated value(4) All of these methods are highly dependent on the respondents

Weakness of Field Methods

Although field methods can be extremely useful because they are conducted in the users natural environment, theyhave some major limitations to consider. The limitations include:(1) Usually take more time and resources than other methods(2) Very high effort in planning, recruiting, and executing than other methods(3) Much longer study periods and therefore requires much goodwill among the participants(4) Studies are longitudinal in nature, therefore, attrition can become a problem[9] .

Application of Human Factors Engineering

An Example: Human Factors Engineering Applied to the MilitaryBefore World War II, HFE had no significance in the design of machines. Consequently, many fatal human errorsduring the war were directly or indirectly related to the absence of comprehensive HFE analyses in the design andmanufacturing process. One of the reasons for so many costly errors was the fact that the capabilities of the humanwere not clearly differentiated from those of the machine.Furthermore, human performance capabilities, skill limitation, and response tendencies were not adequatelyconsidered in the designs of the new systems that were being produced so rapidly during the war. For example, pilotswere often trained on one generation of aircraft, but by the time they got to the war zone, they were required to fly anewer model. The newer model was usually more complex than the older one and, even more detrimental, thecontrols may have had opposing functions assigned to them. Some aircraft required that the control stick be pulledback toward the pilot in order to pull the nose up. In other aircraft the exact opposite was required; namely, in orderto ascend you would push the stick away from you. Needless to say, in an emergency situation many pilots becameconfused and performed the incorrect maneuver, with disastrous results.Along the same line, pilots were subject to substitution errors due mostly to lack of uniformity of control design,inadequate separation of controls, or the lack of a coding system to help the pilot identify controls by the sense oftouch alone. For example, in the early days of retractable landing gear, pilots often grabbed the wrong lever andmistakenly raised the landing gear instead of the flaps. Sensory overload also became a problem, especially incockpit design. The 1950s brought a strong program of standardizing control shapes, locations and overloadmanagement.The growth of human factors engineering during the mid- to late-forties was evidenced by the establishment ofseveral organizations to conduct psychological research on equipment design. Toward the end of 1945, Paul Fittsestablished what came to be known as the Behavioral Sciences Laboratory at the Army Corps AeromedicalLaboratory in Dayton, Ohio. Around the same time, the U.S. Navy established the Naval Research Laboratory atAnacostia, Maryland (headed by Frank V. Taylor), and the Navy Special Devices Center at Port Washington, NewYork (headed by Leonard C. Mead). The Navy Electronics Laboratory in San Diego, California, was establishedabout a year later with Arnold M. Small as head.

Human factors 8

In addition to the establishment of these military organizations, the human factors discipline expanded within severalcivilian activities. Contract support was provided by the U.S. Navy and the U.S. Air Force for research at severalnoted universities, specifically Johns Hopkins, Tufts, Harvard, Maryland, Holyoke, and California (Berkeley).Paralleling this growth was the establishment of several private corporate ventures. Thus, as a direct result of theefforts of World War II, a new industry known as engineering psychology or human factors engineering was born.

Why is HFE important to the military?Until today, many project managers and designers are still slow to consider Human Factors Engineering (HFE) as anessential and integral part of the design process. This is sometimes due to their lack of education on the purpose ofHFE, in other instances it is due to others being perfectly capable of considering HFE related issues. Nevertheless,progress is being made as HFE is becoming more and more accepted and is now implemented in a wide variety ofapplications and processes. The U.S. military is particularly concerned with the implementation of HFE in everyphase of the acquisition process of its systems and equipment. Just about every piece of gear, from a multi-billiondollar aircraft carrier to the boots that Servicemembers wear, goes at least in part through some HFE analyses beforeprocurement and throughout its lifecycle.Lessons learned in the aftermath of World War II prompted the U.S. War Department (now U.S. Department ofDefense) to take some steps in improving safety in military operations. U.S. Department of Defense regulationsrequire a comprehensive management and technical strategy for human systems integration (HSI)[10] be initiatedearly in the acquisition process to ensure that human performance is considered throughout the system design anddevelopment process.[11]

HFE applications in the U.S. ArmyIn the U.S. Army, the term MANPRINT is used as the program designed to implement HSI.[12] [13] The program wasestablished in 1984 with a primary objective to place the human element (functioning as individual, crew/team, unitand organization) on an equal footing with other design criteria such as hardware and software. The entry point ofMANPRINT in the acquisition process is through requirements documents and studies.What is MANPRINT?

MANPRINT (Manpower and Personnel Integration) is a comprehensive management and technical program thatfocuses attention on human capabilities and limitations throughout the system’s life cycle: concept development, testand evaluation, documentation, design, development, fielding, post-fielding, operation and modernization ofsystems. It was initiated in recognition of the fact that the human is an integral part of the total system. If the humanpart of the system can't perform efficiently, the entire system will function sub-optimally.MANPRINT's goal is to optimize total system performance at acceptable cost and within human constraints. This isachieved by the continuous integration of seven human-related considerations (known as MANPRINT domains)with the hardware and software components of the total system and with each other, as appropriate. The sevenMANPRINT domains are: Manpower (M), Personnel (P), Training (T), Human Factors Engineering (HFE), SystemSafety (SS), Health Hazards (HH), Soldier Survivability (SSv). They are each expounded on below:Manpower (M)

Manpower addresses the number of military and civilian personnel required and potentially available to operate,maintain, sustain, and provide training for systems.[14] It is the number of personnel spaces (required or authorizedpositions) and available people (operating strength). It considers these requirements for peacetime, conflict, and lowintensity operations. Current and projected constraints on the total size of the Army/organization/unit are alsoconsidered. The MANPRINT practitioner evaluates the manpower required and/or available to support a new systemand subsequently considers these constraints to ensure that the human resource demands of the system do not exceedthe projected supply.

Human factors 9

Personnel (P)

Manpower and personnel are closely related. While manpower looks at numbers of spaces and people, the domain ofpersonnel addresses the cognitive and physical characteristics and capabilities required to be able to train for,operate, maintain, and sustain materiel and information systems. Personnel capabilities are normally reflected asknowledge, skills, abilities, and other characteristics (KSAOs). The availability of personnel and their KSAOsshould be identified early in the acquisition process and may result in specific thresholds. On most systems,emphasis is placed on enlisted personnel as the primary operators, maintainers, and supporters of the system.Personnel characteristics of enlisted personnel are easier to quantify since the Armed Services Vocational AptitudeBattery (ASVAB) is administered to potential enlistees.While normally enlisted personnel are operators and maintainers; that is not always the case, especially in aviationsystems. Early in the requirements determination process, identification of the target audience should beaccomplished and used as a baseline for assessment. Cognitive and physical demands of the system should beassessed and compared to the projected supply. MANPRINT also takes into consideration personnel factors such asavailability, recruitment, skill identifiers, promotion, and assignment.Training (T)

Training is defined as the instruction or education, on-the-job, or self development training required to provide allpersonnel and units with their essential job skills, and knowledge. Training is required to bridge the gap between thetarget audiences' existing level of knowledge and that required to effectively operate, deploy/employ, maintain andsupport the system. The MANPRINT goal is to acquire systems that meet the Army's training thresholds foroperation and maintenance. Key considerations include developing an affordable, effective and efficient trainingstrategy (which addresses new equipment, training devices, institutional, sustainment, and unit collective tacticaltraining); determining the resources required to implement it in support of fielding and the most efficient method fordissemination (contractor, distance learning, exportable packages, etc.); and evaluating the effectiveness of thetraining.Training is particularly crucial in the acquisition and employment of a new system. New tasks may be introducedinto a duty position; current processes may be significantly changed; existing job responsibilities may be redefined,shifted, or eliminated; and/or entirely new positions may be required. It is vital to consider the total training impactof the system on both the individuals and the organization as a whole.Human Factors Engineering (HFE)

The goal of HFE is to maximize the ability of an individual or crew to operate and maintain a system at requiredlevels by eliminating design-induced difficulty and error. Human factors engineers work with systems engineers todesign and evaluate human-system interfaces to ensure they are compatible with the capabilities and limitations ofthe potential user population. HFE is conducted during all phases of system development, to include requirementsspecification, design and testing and evaluation. HFE activities during requirements specification include: evaluatingpredecessor systems and operator tasks; analyzing user needs; analyzing and allocating functions; and analyzingtasks and associated workload. During the design phase, HFE activities include: evaluating alternative designsthrough the use of equipment mockups and software prototypes; evaluating software by performing usability testing;refining analysis of tasks and workload; and using modeling tools such as human figure models to evaluate crewstation and workplace design and operator procedures. During the testing and evaluation phase, HFE activitiesinclude: confirming the design meets HFE specification requirements; measuring operator task performance; andidentifying any undesirable design or procedural features.System Safety (SS)

System Safety is the design features and operating characteristics of a system that serve to minimize the potential forhuman or machine errors or failures that cause injurious accidents. Safety considerations should be applied in systemacquisition to minimize the potential for accidental injury of personnel and mission failure.

Human factors 10

Health Hazards (HH)

Health Hazards addresses the design features and operating characteristics of a system that create significant risks ofbodily injury or death. Along with safety hazards, an assessment of health hazards is necessary to determine riskreduction or mitigation. The goal of the Health Hazard Assessment (HHA) is to incorporate biomedical knowledgeand principles early in the design of a system to eliminate or control health hazards. Early application will eliminatecostly system retrofits and training restrictions resulting in enhanced soldier-system performance, readiness and costsavings. HHA is closely related to occupational health and preventive medicine but gets its distinctive character fromits emphasis on soldier-system interactions of military unique systems and operations.Health Hazard categories include acoustic energy, biological substances, chemical substances, oxygen deficiency,radiation energy, shock, temperature extremes and humidity, trauma, vibration, and other hazards. Health hazardsinclude those areas that could cause death, injury, illness, disability, or a reduction in job performance.Organisational and Social

The seventh domain addresses the human factors issues associated with the socio-technical systems necessary formodern warfare. This domain has been recently added to investigate issues specific to Network Enabled Capability(NEC) also known as Network Centric Warfare (NCW). Elements such as dynamic command and control structures,data assimilation across mulitple platforms and its fusion into information easily understood by distributed operatorsare some of the issues investigated.A soldier survivability domain was also proposed but this was never fully integrated into the MANPRINT model.Domain Integration

Although each of the MANPRINT domains has been introduced separately, in practice they are often interrelatedand tend to impact on one another. Changes in system design to correct a deficiency in one MANPRINT domainnearly always impact another domain.

Human Factors IntegrationAreas of interest for human factors practitioners may include: training, staffing evaluation, communication, taskanalyses, functional requirements analyses and allocation, job descriptions and functions, procedures and procedureuse, knowledge, skills, and abilities; organizational culture, human-machine interaction, workload on the human,fatigue, situational awareness, usability, user interface, learnability, attention, vigilance, human performance, humanreliability, human-computer interaction, control and display design, stress, visualization of data, individualdifferences, aging, accessibility, safety, shift work, work in extreme environments including virtual environments,human error, and decision making.

Real World Applications of Human Factors - MultiModal InterfacesMulti-Modal Interfaces

In many real world domains, ineffective communication occurs partially because of inappropriate and ineffectivepresentation of information. Many real world interfaces both allow user input and provide user output in a singlemodality (most often being either visual or auditory). This single modality presentation can often lead to dataoverload in that modality causing the user to become overwhelmed by information and cause him/her to overlooksomething. One way to address this issue is to use multi-modal interfaces.Reasons to Use Multimodal Interfaces

• Time Sharing – helps avoid overloading one single modality• Redundancy – providing the same information in two different modalities helps assure that the user will see the

information• Allows for more diversity in users (blind can use tactile input; hearing impaired can use visual input and output)

Human factors 11

• Error Prevention – having multiple modalities allows the user to choose the most appropriate modality for eachtask (for example, spatial tasks are best done in a visual modality and would be much harder in an olfactorymodality)

Examples of Well Known Multi-Modality Interfaces

• Cell Phone – The average cell phone uses auditory, visual, and tactile output through use of a phone ringing,vibrating, and a visual display of caller ID.

• ATM – Both auditory and visual outputsEarly Multi-Modal Interfaces by the Experts

• Bolts “Put That There” – 1980 – used speech and manual pointing• Cohen and Oviatt’s “Quickset” – multi user speech and gesture input

Worker Safety and HealthOne of the most prevalent types of work-related injuries are musculoskeletal disorders. Work-relatedmusculoskeletal disorders (WRMDs) result in persistent pain, loss of functional capacity and work disability, buttheir initial diagnosis is difficult because they are mainly based on complaints of pain and other symptoms.[15] Everyyear 1.8 million U.S. workers experience WRMDs and nearly 600,000 of the injuries are serious enough to causeworkers to miss work.[16] Certain jobs or work conditions cause a higher rate worker complaints of undue strain,localized fatigue, discomfort, or pain that does not go away after overnight rest. These types of jobs are often thoseinvolving activities such as repetitive and forceful exertions; frequent, heavy, or overhead lifts; awkward workpositions; or use of vibrating equipment.[17] The Occupational Safety and Health Administration (OSHA) has foundsubstantial evidence that ergonomics programs can cut workers' compensation costs, increase productivity anddecrease employee turnover.[18] Therefore, it is important to gather data to identify jobs or work conditions that aremost problematic, using sources such as injury and illness logs, medical records, and job analyses.[17]

Job analyses can be carried out using methods analysis, time studies, work sampling, or other established workmeasurement systems.• Methods Analysis is the process of studying the tasks a worker completes using a step-by-step investigation. Each

task in broken down into smaller steps until each motion the worker performs is described. Doing so enables youto see exactly where repetitive or straining tasks occur.

• Time studies determine the time required for a worker to complete each task. Time studies are often used toanalyze cyclical jobs. They are considered “event based” studies because time measurements are triggered by theoccurrence of predetermined events.[19]

• Work Sampling is a method in which the job is sampled at random intervals to determine the proportion of totaltime spent on a particular task.[19] It provides insight into how often workers are performing tasks which mightcause strain on their bodies.

• Predetermined time systems are methods for analyzing the time spent by workers on a particular task. One of themost widely used predetermined time system is called Methods-Time-Measurement or MTM. Other commonwork measurement systems include MODAPTS and MOST.

Human factors 12

See also• Alphonse Chapanis• Crew Resource Management• Engineering psychology• Ergonomics• Experience design• High velocity human factors• Human-centered computing (discipline)• Human computer interaction• Human-in-the-Loop• Human reliability• Industrial Engineering• Industrial Design• Latent human error• Maintenance Resource Management (MRM)• Mockup• Paul Fitts• Single pilot resource management• System Usability Scale (SUS)• Systems engineering• Ubiquitous computing• Usability• User-centered design• User experience design

Additional reading• Meister, D. (1999). The History of Human Factors and Ergonomics. Mahwah, N.J.: Lawrence Erlbaum

Associates. ISBN 0805827692.• Oviatt, S. L.; Cohen, P. R. (2000, March). "Multimodal systems that process what comes naturally".

Communications of the ACM (New York: ACM Press) 43: 45–53.• Sarter, N. B.; Cohen, P. R. (2002). "Multimodal information presentation in support of human-automation

communication and coordination". Advances in Human Performance and Cognitive Engineering Research(Netherlands: JAI) 2: 13–36.

• Wickens, C.D.; Lee J.D.; Liu Y.; Gorden Becker S.E. (1997). An Introduction to Human Factors Engineering,2nd Edition. Prentice Hall. ISBN 0321012291.

• Wickens, C. D.; Sandy, D. L.; Vidulich, M. (1983). "Compatibility and resource competition between modalitiesof input, central processing, and output". Human Factors (Santa Monica, CA, ETATS-UNIS: Human Factors andErgonomics Society) 25 (2): 227–248. ISSN 00187208. PMID 6862451.

Human factors 13

Related software• 3D SSPP• ErgoFellow

External links• Directory of Design Support Methods [20]

• Engineering Data Compendium of Human Perception and Performance [21]

• Index of Non-Government Standards on Human Engineering... [22]

• Index of Government Standards on Human Engineering... [23]

• Human Factors Engineering resources [24]

• MANPRINT [25]

• Human Factors in aviation [26]

References[1] Porter, Elias H. (1964). Manpower Development: The System Training Concept. New York: Harper and Row, p. xiii.[2] The History of Human Factors and Ergonomics, David Meister[3] Stanton, N.; Salmon, P., Walker G., Baber, C., Jenkins, D. (2005). Human Factors Methods; A Practical Guide For Engineering and Design..

Aldershot, Hampshire: Ashgate Publishing Limited. ISBN 0754646610.[4] Carrol, J.M. (1997). Human-Computer Interaction: Psychology as a Science of Design. Annu. Rev. Psyc., 48, 61-83.[5] http:/ / www. nedarc. org/ nedarc/ media/ pdf/ surveyMethods_2006. pdf[6] Wickens, C.D.; Lee J.D.; Liu Y.; Gorden Becker S.E. (1997). An Introduction to Human Factors Engineering, 2nd Edition. Prentice Hall.

ISBN 0321012291.[7] Kuusela, H., Paul, P. (2000). A comparison of concurrent and retrospective verbal protocol analysis. The American Journal of Psychology,

113, 387-404.[8] Hornbaek, K (2006). Current Practice in Measuring Usability: Challenges to Usability Studies and Research, International Journal of

Human-Computer Studies.[9] Dumas, J. S.; Salzman, M.C. (2006). Reviews of Human Factors and Ergonomics. 2. Human Factors and Ergonomics Society.[10] human systems integration (HSI) (https:/ / akss. dau. mil/ dag/ Guidebook/ IG_c6. 0. asp)[11] DoD 5000.2-R (http:/ / www. acq. osd. mil/ ie/ bei/ pm/ ref-library/ dodi/ p50002r. pdf) (Paragraph 4.3.8)[12] MANPRINT website (http:/ / www. manprint. army. mil/ )[13] (https:/ / akss. dau. mil/ dag/ Guidebook/ IG_c6. 0. asp)[14] Title 10, U. S. Code Armed Forces, Sec. 2434 (http:/ / www. access. gpo. gov/ uscode/ title10/ subtitlea_partiv_chapter144_. html)[15] Isabel A P Walsh; Jorge Oishi; Helenice J C Gil Coury (February 2008). "Clinical and functional aspects of work-related musculoskeletal

disorders among active workers". . Programa de Pós-graduação em Fisioterapia. Universidade Federal de São Carlos. São Carlos, SP,Brasil. Rev. Saúde Pública vol.42 no.1 São Paulo.

[16] Charles N. Jeffress (October 27, 2000). "BEACON Biodynamics and Ergonomics Symposium". University of Connecticut, Farmington,Conn..

[17] "Workplace Ergonomics: NIOSH Provides Steps to Minimize Musculoskeletal Disorders" (http:/ / www. buildings. com/ articles/ detail.aspx?contentID=1563). 2003. . Retrieved 2008-04-23.

[18] Charles N. Jeffress (October 27, 2000). BEACON Biodynamics and Ergonomics Symposium. University of Connecticut, Farmington, Conn..[19] Thomas J. Armstrong (2007). Measurement and Design of Work.[20] http:/ / www. dtic. mil/ dticasd/ ddsm/[21] http:/ / www. dtic. mil/ dticasd/ edc/ TOC/ EDCTOC. html[22] http:/ / hfetag. dtic. mil/ docs/ index_ngs. doc[23] http:/ / hfetag. dtic. mil/ docs/ index_govt_std. doc[24] http:/ / www. humanics-es. com/ recc-ergonomics. htm#humanfactorsergonomics[25] http:/ / www. manprint. army. mil/[26] http:/ / www. skybrary. aero/ index. php/ Category:Human_Factors

Ergonomics 14

Ergonomics

Ergonomics: the science of designing the job, equipment, andworkplace to fit the worker.

Ergonomics is the science of designing the job,equipment, and workplace to fit the worker. Properergonomic design is necessary to prevent repetitive straininjuries, which can develop over time and can lead tolong-term disability.[1]

The International Ergonomics Association definesergonomics as follows:[2]

Ergonomics (or human factors) is the scientificdiscipline concerned with the understanding ofinteractions among humans and other elements of asystem, and the profession that applies theory,principles, data and methods to design in order tooptimize human well-being and overall systemperformance.

Ergonomics is employed to fulfill the two goals of healthand productivity. It is relevant in the design of suchthings as safe furniture and easy-to-use interfaces tomachines.

Overview

Ergonomics is concerned with the ‘fit’ between peopleand their technological tools and environments. It takesaccount of the user's capabilities and limitations inseeking to ensure that tasks, equipment, information andthe environment suit each user.

To assess the fit between a person and the used technology, ergonomists consider the job (activity) being done andthe demands on the user; the equipment used (its size, shape, and how appropriate it is for the task), and theinformation used (how it is presented, accessed, and changed). Ergonomics draws on many disciplines in its study ofhumans and their environments, including anthropometry, biomechanics, mechanical engineering, industrialengineering, industrial design, kinesiology, physiology and psychology.

Typically, an ergonomist will have a BA or BS in Psychology, Industrial/Mechanical Engineering or IndustrialDesign or Health Sciences, and usually an MA, MS or PhD in a related discipline. Many universities offer Master ofScience degrees in Ergonomics, while some offer Master of Ergonomics or Master of Human Factors degrees. In the2000s, occupational therapists have been moving into the field of ergonomics and the field has been heralded as oneof the top ten emerging practice areas.[3]

Ergonomics 15

DomainsThe International Ergonomics Association (IEA) divides ergonomics broadly into three domains:• Physical ergonomics: is concerned with human anatomical, and some of the anthropometric, physiological and

biomechanical characteristics as they relate to physical activity. (Relevant topics include working postures,materials handling, repetitive movements, lifting, work related musculoskeletal disorders, workplace layout,safety and health.)

• Cognitive ergonomics: is concerned with mental processes, such as perception, memory, reasoning, and motorresponse, as they affect interactions among humans and other elements of a system. (Relevant topics includemental workload, decision-making, skilled performance, human-computer interaction, human reliability, workstress and training as these may relate to human-system and Human-Computer Interaction design.)

• Organizational ergonomics: is concerned with the optimization of socio technical systems, including theirorganizational structures, policies, and processes.(Relevant topics include communication, crew resourcemanagement, work design, design of working times, teamwork, participatory design, community ergonomics,cooperative work, new work programs, virtual organizations, telework, and quality management.

History and etymologyThe foundations of the science of ergonomics appear to have been laid within the context of the culture of AncientGreece. A good deal of evidence indicates that Hellenic civilization in the 5th century BC used ergonomic principlesin the design of their tools, jobs, and workplaces. One outstanding example of this can be found in the descriptionHippocrates gave of how a surgeon's workplace should be designed and how the tools he uses should be arranged(see Marmaras, Poulakakis and Papakostopoulos, 1999) [4] . It is also true that archaeological records of the earlyEgyptians Dynasties made tools, household equipment, among others that illustrated ergonomic principles. It istherefore questionable whether the claim by Marmaras, et al., regarding the origin of ergonomics, can be justified (IG Okorji, 2009).The term ergonomics is derived from the Greek words ergon [work] and nomos [natural laws] and first entered themodern lexicon when Wojciech Jastrzębowski used the word in his 1857 article Rys ergonomji czyli nauki o pracy,opartej na prawdach poczerpniętych z Nauki Przyrody (The Outline of Ergonomics, i.e. Science of Work, Based onthe Truths Taken from the Natural Science).Later, in the 19th century, Frederick Winslow Taylor pioneered the "Scientific Management" method, whichproposed a way to find the optimum method for carrying out a given task. Taylor found that he could, for example,triple the amount of coal that workers were shoveling by incrementally reducing the size and weight of coal shovelsuntil the fastest shoveling rate was reached. Frank and Lillian Gilbreth expanded Taylor's methods in the early 1900sto develop "Time and Motion Studies". They aimed to improve efficiency by eliminating unnecessary steps andactions. By applying this approach, the Gilbreths reduced the number of motions in bricklaying from 18 to 4.5,allowing bricklayers to increase their productivity from 120 to 350 bricks per hour.World War II marked the development of new and complex machines and weaponry, and these made new demandson operators' cognition. The decision-making, attention, situational awareness and hand-eye coordination of themachine's operator became key in the success or failure of a task. It was observed that fully functional aircraft, flownby the best-trained pilots, still crashed. In 1943, Alphonse Chapanis, a lieutenant in the U.S. Army, showed that thisso-called "pilot error" could be greatly reduced when more logical and differentiable controls replaced confusingdesigns in airplane cockpits.In the decades since the war, ergonomics has continued to flourish and diversify. The Space Age created new human factors issues such as weightlessness and extreme g-forces. How far could environments in space be tolerated, and what effects would they have on the mind and body? The dawn of the Information Age has resulted in the new ergonomics field of human-computer interaction (HCI). Likewise, the growing demand for and competition among

Ergonomics 16

consumer goods and electronics has resulted in more companies including human factors in product design.However, the coining of the term Ergonomics is now widely attributed to Hywel Murrell, a psychologist in ameeting at the UK admiralty in 1949. He used it to encompass the studies on which he had been engaged during andafter the Second World War.[5]

ApplicationsMore than twenty technical subgroups within the Human Factors and Ergonomics Society [6] (HFES) indicate therange of applications for ergonomics. Human factors engineering continues to be successfully applied in the fields ofaerospace, aging, health care, IT, product design, transportation, training, nuclear and virtual environments, amongothers. Kim Vicente, a University of Toronto Professor of Ergonomics, argues that the nuclear disaster in Chernobylis attributable to plant designers not paying enough attention to human factors. "The operators were trained but thecomplexity of the reactor and the control panels nevertheless outstripped their ability to grasp what they were seeing[during the prelude to the disaster]."Physical ergonomics is important in the medical field, particularly to those diagnosed with physiological ailments ordisorders such as arthritis (both chronic and temporary) or carpal tunnel syndrome. Pressure that is insignificant orimperceptible to those unaffected by these disorders may be very painful, or render a device unusable, for those whoare. Many ergonomically designed products are also used or recommended to treat or prevent such disorders, and totreat pressure-related chronic pain.Human factors issues arise in simple systems and consumer products as well. Some examples include cellulartelephones and other handheld devices that continue to shrink yet grow more complex (a phenomenon referred to as"creeping featurism"), millions of VCRs blinking "12:00" across the world because very few people can figure outhow to program them, or alarm clocks that allow sleepy users to inadvertently turn off the alarm when they mean tohit 'snooze'. A user-centered design (UCD), also known as a systems approach or the usability engineering lifecycleaims to improve the user-system.

Design of ergonomics experimentsThere is a specific series of steps that should be used in order to properly design an ergonomics experiment. First,one should select a problem that has practical impact. The problem should support or test a current theory. The usershould select one or a few dependent variable(s) which usually measures safety, health, and/or physiologicalperformance. Independent variable(s) should also be chosen at different levels. Normally, this involves paidparticipants, the existing environment, equipment, and/or software. When testing the users, one should give carefulinstructions describing the method or task and then get voluntary consent. The user should recognize all the possiblecombinations and interactions to notice the many differences that could occur. Multiple observations and trialsshould be conducted and compared to maximize the best results. Once completed, redesigning within and betweensubjects should be done to vary the data. It is often that permission is needed from the Institutional Review Boardbefore an experiment can be done. A mathematical model should be used so that the data will be clear once theexperiment is completed.The experiment starts with a pilot test. Make sure in advance that the subjects understand the test, the equipmentworks, and that the test is able to be finished within the given time. When the experiment actually begins, thesubjects should be paid for their work. All times and other measurements should be carefully measured and recorded.Once all the data is compiled, it should be analyzed, reduced, and formatted in the right way. A report explaining theexperiment should be written. It should often display statistics including an ANOVA table, plots, and means ofcentral tendency. A final paper should be written and edited after numerous drafts to ensure an adequate report is thefinal product.

Ergonomics 17

Ergonomics in the workplace

Fundamentals for the Flexible Workplace Variability andcompatibility with desk components, that flex from individual

work activities to team settings. Workstations provide supportiveergonomics for task-intensive environments.[7]

Outside of the discipline itself, the term 'ergonomics' isgenerally used to refer to physical ergonomics as it relatesto the workplace (as in for example ergonomic chairs andkeyboards). Ergonomics in the workplace has to dolargely with the safety of employees, both long andshort-term. Ergonomics can help reduce costs byimproving safety. This would decrease the money paidout in workers’ compensation. For example, over fivemillion workers sustain overextension injuries per year.Through ergonomics, workplaces can be designed so thatworkers do not have to overextend themselves and themanufacturing industry could save billions in workers’compensation.

Workplaces may either take the reactive or proactive approach when applying ergonomics practices. Reactiveergonomics is when something needs to be fixed, and corrective action is taken. Proactive ergonomics is the processof seeking areas that could be improved and fixing the issues before they become a large problem. Problems may befixed through equipment design, task design, or environmental design. Equipment design changes the actual,physical devices used by people. Task design changes what people do with the equipment. Environmental designchanges the environment in which people work, but not the physical equipment they use.

Fields of ergonomics

Engineering psychologyEngineering psychology is an interdisciplinary part of ergonomics and studies the relationships of people tomachines, with the intent of improving such relationships. This may involve redesigning equipment, changing theway people use machines, or changing the location in which the work takes place. Often, the work of an engineeringpsychologist is described as making the relationship more "user-friendly."Engineering psychology is an applied field of psychology concerned with psychological factors in the design and useof equipment. Human factors is broader than engineering psychology, which is focused specifically on designingsystems that accommodate the information-processing capabilities of the brain.[8]

MacroergonomicsMacroergonomics is an approach to ergonomics that emphasizes a broad system view of design, examiningorganizational environments, culture, history, and work goals. It deals with the physical design of tools and theenvironment. It is the study of the society/technology interface and their consequences for relationships, processes,and institutions. It also deals with the optimization of the designs of organizational and work systems through theconsideration of personnel, technological, and environmental variables and their interactions. The goal ofmacroergonomics is a completely efficient work system at both the macro- and micro-ergonomic level which resultsin improved productivity, and employee satisfaction, health, safety, and commitment. It analyzes the whole system,finds how each element should be placed in the system, and considers all aspects for a fully efficient system. Amisplaced element in the system can lead to total failure.HistoryMacroergonomics, also known as organizational design and management factors, deals with the overall design ofwork systems. This domain did not begin to receive recognition as a sub-discipline of ergonomics until the beginning

Ergonomics 18

of the 1980s. The idea and current perspective of the discipline was the work of the U.S. Human Factors SocietySelect Committee on the Future of Human Factors, 1980-2000. This committee was formed to analyze trends in allaspects of life and to look at how they would impact ergonomics over the following 20 years. The developments theyfound include:1. Breakthroughs in technology that would change the nature of work, such as the desktop computer,2. The need for organizations to adapt to the expectations and needs of this more mature workforce,3. Differences between the post-World War II generation and the older generation regarding their expectations the

nature of the new workplace,4. The inability of solely microergonomics to achieve reductions in lost-time accidents and injuries and increases in

productivity,5. Increasing workplace liability litigation based on safety design deficiencies.These predictions have become and continue to become reality. The macroergonomic intervention in the workplacehas been particularly effective in establishing a work culture that promotes and sustains performance and safetyimprovements.Methods[9]

• Cognitive Walk-through Method: This method is a usability inspection method in which the evaluators can applyuser perspective to task scenarios to identify design problems. As applied to macroergonomics, evaluators areable to analyze the usability of work system designs to identify how well a work system is organized and howwell the workflow is integrated.

• Kansei Method: This is a method that transforms consumer’s responses to new products into design specifications.As applied to macroergonomics, this method can translate employee’s responses to changes to a work system intodesign specifications.

• High Integration of Technology, Organization, and People (HITOP): This is a manual procedure donestep-by-step to apply technological change to the workplace. It allows managers to be more aware of the humanand organizational aspects of their technology plans, allowing them to efficiently integrate technology in thesecontexts.

• Top Modeler: This model helps manufacturing companies identify the organizational changes needed when newtechnologies are being considered for their process.

• Computer-integrated Manufacturing, Organization, and People System Design (CIMOP): This model allows forevaluating computer-integrated manufacturing, organization, and people system design based on knowledge ofthe system.

• Anthropotechnology: This method considers analysis and design modification of systems for the efficient transferof technology from one culture to another.

• Systems Analysis Tool (SAT): This is a method to conduct systematic trade-off evaluations of work-systemintervention alternatives.

• Macroergonomic Analysis of Structure (MAS): This method analyzes the structure of work systems according totheir compatibility with unique sociotechnical aspects.

• Macroergonomic Analysis and Design (MEAD): This method assesses work-system processes by using a ten-stepprocess.

Ergonomics 19

Seating ergonomicsThe best way to reduce pressure in the back is to be in a standing position. However, there are times when you needto sit. When sitting, the main part of the body weight is transferred to the seat. Some weight is also transferred to thefloor, back rest, and armrests. Where the weight is transferred is the key to a good seat design. When the proper areasare not supported, sitting in a seat all day can put unwanted pressure on the back causing pain.The lumbar (bottom five vertebrate in the spine) needs to be supported to decrease disc pressure. Providing both aseat back that inclines backwards and has a lumbar support is critical to prevent excessive low back pressures. Thecombination which minimizes pressure on the lower back is having a backrest inclination of 120 degrees and alumbar support of 5 cm. The 120 degrees inclination means the angle between the seat and the backrest should be120 degrees. The lumbar support of 5 cm means the chair backrest supports the lumbar by sticking out 5 cm in thelower back area. One drawback to creating an open body angle by moving the backrest backwards is that it takesones body away from the tasking position, which typically involves leaning inward towards a desk or table. Onesolution to this problem can be found in the kneeling chair. A proper kneeling chair creates the open body angle bylowering the angle of the lower body, keeping the spine in alignment and the sitter properly positioned to task. Thebenefit of this position is that if one leans inward, the body angle remains 90 degrees or wider. One mis-perceptionregarding kneeling chairs is that the body's weight bears on the knees, and thus users with poor knees cannot use thechair. This misperception has led to a generation of kneeling chairs that attempt to correct this by providing ahorizontal seating surface with an ancillary knee pad. This design wholly defeats the purpose of the chair. In a properkneeling chair, some of the weight bears on the shins, not the knees, but the primary function of the shin rests (kneerests) are to keep one from falling forward out of the chair. Most of the weight remains on the buttocks. Another wayto keep the body from falling forward is with a saddle seat. This type of seat is generally seen in some sit standstools, which seek to emulate the riding or saddle position of a horseback rider, the first "job" involving extendedperiods of sitting.Another key to reducing lumbar disc pressure is the use of armrests. They help by putting the force of your body notentirely on the seat and back rest, but putting some of this pressure on the armrests. Armrest needs to be adjustable inheight to assure shoulders are not overstressed.

OrganizationsThe International Ergonomics Association [10] (IEA) is a federation of ergonomics and human factors societies fromaround the world. The mission of the IEA is to elaborate and advance ergonomics science and practice, and toimprove the quality of life by expanding its scope of application and contribution to society. As of September 2008,the International Ergonomics Association has 46 federated societies and 2 affiliated societies.The International Society of Automotive Engineers (SAE) is a professional organization for mobility engineeringprofessionals in the aerospace, automotive, and commercial vehicle industries. The Society is a standardsdevelopment organization for the engineering of powered vehicles of all kinds, including cars, trucks, boats, aircraft,and others. The Society of Automotive Engineers has established a number of standards used in the automotiveindustry and elsewhere. It encourages the design of vehicles in accordance with established Human Factorsprinciples. It is one the most influential organizations with respect to Ergonomics work in Automotive Design. Thissociety regularly holds conferences which address topics spanning all aspects of Human Factors/Ergonomics.In the UK the professional body for ergonomists is the The Institute of Ergonomics and Human Factors and in theUSA it is the Human Factors and Ergonomics Society [11]. In Europe professional certification is managed by theCentre for Registration of European Ergonomists [12] (CREE). In the USA the Board of Certification in ProfessionalErgonomics [13] performs this function.

Ergonomics 20

See also

Related subjects

• Back injury• Carpal tunnel syndrome• Cognitive ergonomics• Cognitive load• Human-computer interaction• Industrial noise• Manual handling• Occupational health psychology• Repetitive strain injury• Rohmert's law

Related fields

• Anthropometrics• Design for All• Environmental design• Industrial Design• Industrial hygiene• Activity-centered ergonomics• Human factors• Light ergonomics• Occupational therapy• Participatory Ergonomics• Systems engineering• Systems psychology

Related scientists

• Shihab S. Asfour• M. M. Ayoub• Alphonse Chapanis• Henry Dreyfuss• W. E. Hick• John Chris Jones• Neville A. Stanton

Further readingBooks• Jan Dul and Bernard Weerdmeester, Ergonomics for Beginners - - A classic introduction on ergonomics -

Original title: Vademecum Ergonomie (Dutch) -published and updated since 1960's• Stephen Pheasant, Bodyspace - - A classic exploration of ergonomics• Kim Vicente, The Human Factor Full of examples and statistics illustrating the gap between existing technology

and the human mind, with suggestions to narrow it• Donald Norman, The Design of Everyday Things - - An entertaining user-centered critique of nearly every gadget

out there (at the time it was published)• Liu, Y (2007). IOE 333. Course pack. Industrial and Operations Engineering 333 (Introduction to Ergonomics),

University of Michigan, Ann Arbor, MI. Winter 2007• Wilson & Corlett, Evaluation of Human Work A practical ergonomics methodology. Warning: very technical and

not a suitable 'intro' to ergonomics• Wickens and Hollands (200). Engineering Psychology and Human Performance. Discusses memory, attention,

decision making, stress and human error, among other topics• Alvin R. Tilley & Henry Dreyfuss Associates (1993, 2002), The Measure of Man & Woman: Human Factors in

Design A human factors design manual.• Valerie J Gawron (2000), Human Performance Measures Handbook Lawrence Erlbaum Associates - A useful

summary of human performance measures.• Peter Opsvik (2009), "Re-Thinking Sitting" Interesting insights on the history of the chair and how we sit from an

ergonomic pioneer• Thomas J. Armstrong (2008), Chapter 10: Allowances, Localized Fatigue, Musculoskeletal Disorders, and

Biomechanics (not yet published)Peer-reviewed Publications

(numbers between brackets are the ISI impact factor 2001-2003)• Behaviour & Information Technology (0.915 (2008))• Ergonomics (0.747)• Applied Ergonomics (0.738)• Human Factors (0.723)• International Journal of Industrial Ergonomics (0.395)• Human Factors and Ergonomics in Manufacturing (0.311)• Travail Humain (0.260)

Ergonomics 21

• Theoretical Issues in Ergonomics Science (-)• International Journal of Occupational Safety and Ergonomics (-)

Related software• 3DSSPP• ErgoFellow• RAMSIS

External links• Human Factors and Ergonomics resources [24]

• NIOSH Topic Page on Ergonomics and Musculoskeletal Disorders [14]

• Office Ergonomics Information [15] from European Agency for Safety and Health at Work• Ergonomic Research Resources [16]

References[1] Berkeley Lab. Integrated Safety Management: Ergonomics (http:/ / www. lbl. gov/ ehs/ pub811/ hazards/ ergonomics. html). Website.

Retrieved 9 July 2008.[2] International Ergonomics Association. What is Ergonomics (http:/ / iea. cc/ browse. php?contID=what_is_ergonomics). Website. Retrieved

21 August 2008.[3] Top 10 Emerging Practice Areas To Watch in the New Millenium (http:/ / www. aota. org/ nonmembers/ area1/ links/ link61. asp), article on

American Occupational Therapy Association web site[4] Marmaras, N., Poulakakis, G. and Papakostopoulos, V. (1999). Ergonomic design in ancient Greece. Applied Ergonomics, 30 (4), pp.

361-368. (http:/ / simor. ntua. gr/ ergou/ people/ CV-MarmarasNicolas. htm)[5] http:/ / www. ergonomics. org. uk/ page. php?p=45& s=5[6] Technical Groups page at HFES Web site (http:/ / www. hfes. org/ web/ TechnicalGroups/ technical. html)[7] Unicor.gov. XXI Notes System Furniture (http:/ / www. unicor. gov/ office_furniture/ overview/ system_furniture/ ssXXInotes/ ). Retrieved 9

July 2008.[8] Wickens, C. and Hollands, J. (1999), Engineering Psychology and Human Performance, Prentice Hall, ISBN 0321047117[9] Brookhuis, K., Hedge, A., Hendrick, H., Salas, E., and Stanton, N. (2005). Handbook of Human Factors and Ergonomics Models. Florida:

CRC Press.[10] http:/ / www. iea. cc[11] http:/ / www. hfes. org[12] http:/ / www. eurerg. org[13] http:/ / www. bcpe. org[14] http:/ / www. cdc. gov/ niosh/ topics/ ergonomics/[15] http:/ / osha. europa. eu/ publications/ e-facts/ efact13/ 13_office_ergonomics. pdf[16] http:/ / www. mcergo. com/ ergo-resources/

Anthropometry 22

AnthropometryAnthropometry (Greek άνθρωπος, man, and μέτρον, measure, literally meaning "measurement of humans"), inphysical anthropology, refers to the measurement of the human individual for the purposes of understanding humanphysical variation.Today, anthropometry plays an important role in industrial design, clothing design, ergonomics and architecturewhere statistical data about the distribution of body dimensions in the population are used to optimize products.Changes in life styles, nutrition and ethnic composition of populations lead to changes in the distribution of bodydimensions (e.g., the obesity epidemic), and require regular updating of anthropometric data collections.

Illustration from "The Speaking Portrait" (Pearson's Magazine, VolXI, January to June 1901) demonstrating the principles of Bertillon's

anthropometry.

History

A Bertillon record for Francis Galton, from a visitto Bertillon's laboratory in 1893.

Bertillon, Galton, and criminology

The savant Alphonse Bertillon gave his name in 1883 to a system ofidentification depending on the unchanging character of certainmeasurements of parts of the human frame. He found by patientinquiry that several measures of physical features, along withdimensions of certain bones, boners or bony structures in the body,remain fairly constant throughout adult life.

He concluded that when these measurements were made and recordedsystematically every single individual would be found to be perfectlydistinguishable from others. The system was soon adapted to policemethods when crime fighters found value in being able to fix a person'sidentity. It prevented false impersonation and brought home, to anyone charged with an offense, a person's responsibility for a

wrongdoing. After its introduction in France in 1883 "Bertillonage," as it was called, became widely popular, andcredited with producing highly gratifying results. Many countries followed suit in the adoption of the method,integrating it within their justice systems.However it was almost a decade before England followed suit when in 1894 a special committee was sent to Parisfor an investigation of the methods used and results obtained with them. It reported back favorably, especially on theuse of measurements for primary classification, but also recommended the adoption, in part, of the system of "fingerprints" as suggested by Francis Galton, and in practice at that time in Bengal, India.

Anthropometry 23

A chart from Bertillon's Identification anthropométrique(1893), demonstrating how to take measurements for his

identification system.

There were eleven measurements:1. Height2. Stretch: Length of body from left shoulder to right

middle finger when arm is raised3. Bust: Length of torso from head to seat, taken when

seated4. Length of head: Crown to forehead5. Width of head: Temple to temple6. Length of right ear7. Length of left foot8. Length of left middle finger9. Length of left cubit: Elbow to tip of middle finger10. Width of cheeksFrom this great mass of details, soon represented in Parisby the collection of some 100,000 cards, it was possible,proceeding by exhaustion, to sift and sort down the cardstill a small bundle of half a dozen produced the combinedfacts of the measurements of the individual last sought.The whole of the information is easily contained in onecabinet of very ordinary dimensions, and most ingeniouslycontrived so as to make the most of the space and facilitatethe search. The whole of the record is independent ofnames, and the final identification is by means of thephotograph which lies with the individual's card ofmeasurements.

Anthropometry 24

Anthropometry demonstrated in an exhibit from a 1921 eugenicsconference.

Anthropometrics was first used in the 19th and early20th century in criminalistics, to identifying criminalsby facial characteristics. Francis Galton was a keycontributor as well, and it was in showing theredundancy of Bertillon's measurements that hedeveloped the statistical concept of correlation.

Bertillon's system originally measured variables hethought were independent - such as forearm length andleg length - but Galton had realized that both were theresult of a single causal variable (in this case, stature).Bertillon's goal was to use anthropometry as a way ofidentifying recidivists—what we would today call"repeat-offense" criminals. Previously, police couldonly record general descriptions and names, andcriminals often used alternative identities or aliases.

As such, it was a difficult job to identify whether or notcertain individuals arrested were "first offenders" orlife-long criminals. Photography of criminals hadbecome commonplace but it had proven ungainly, asthere was no coherent way to arrange visually the manythousands of photographs in a fashion which wouldallow easy use (an officer would have to sort through

them all with the hope of finding one). Bertillon's hope was that through the use of measurements of the body, allinformation about the individual criminal could be reduced to a set of identifying numbers which could be enteredinto a large filing system.Bertillon also envisioned the system as being organized in such a way that even if the number of measurements waslimited the system could drastically reduce the number of potential matches, through an easy system of body partsand characteristics being labeled as "small", "medium", or "large". For example, if the length of the arm wasmeasured and judged to be within the "medium" range, and the size of the foot was known, this would drasticallyreduce the number of potential records to compare against.With more measurements of hopefully independent variables, a more precise identification could be achieved, whichcould then be matched against photographic evidence. Certain aspects of this philosophy would also go into Galton'sdevelopment of fingerprint identification as well.Anthropometry, however, gradually fell into disfavor, and it has been generally supplanted by the superior system offinger prints. Bertillonage exhibited certain defects which were first brought to light in Bengal. The objections raisedwere1. the costliness of the instruments employed and their liability to become out of order;2. the need for specially instructed measurers, men of superior education;3. the errors that frequently crept in when carrying out the processes and were all but irremediable.Measures inaccurately taken, or incorrectly read off, could seldom, if ever, be corrected, and these persistent errorsdefeated all chance of successful search. The process was slow, as it was necessary to repeat it three times so as toarrive at a mean result. In Bengal, measurements were already abandoned by 1897, when the finger print system wasadopted throughout British India. Three years later England followed suit; and as the result of a fresh inquiry orderedby the Home Office, finger prints were alone relied upon for identification.

Anthropometry 25

Anthropology and anthropometry

A "head-measurer" tool designed for anthropological research in theearly 1910s.

During the early 20th century, anthropometry was usedextensively by anthropologists in the United States andEurope. One of its primary uses became the attempteddifferentiation between differences in the races of man,and it was often employed to show ways in which raceswere "inferior" to others.[1] [2]

The wide application of intelligence testing alsobecame incorporated into a general anthropometricapproach, and many forms of anthropometry were usedfor the advocacy of eugenics policies. During the 1920sand 1930s, though, members of the school of culturalanthropology of Franz Boas also began to useanthropometric approaches to discredit the concept offixed biological race.

Anthropometric approaches to these types of problems became abandoned in the years after the Holocaust in NaziGermany, who also famously relied on anthropometric measurements to distinguish Aryans from Jews. This schoolof physical anthropology generally went into decline during the 1940s.During the 1940s anthropometry was used by William Sheldon when evaluating his somatotypes, according to whichcharacteristics of the body can be translated into characteristics of the mind. Inspired by Cesare Lombroso's criminalanthropology, he also believed that criminality could be predicted according to the body type. This use ofanthropometry is today also outdated. Because of his extensive reliance on photographs of nude Ivy League studentsfor his work, Sheldon ran into considerable controversy when his work became public.

Modern anthropometry and biometricsAnthropometric studies are today conducted for numerous different purposes. Academic anthropologists investigatethe evolutionary significance of differences in body proportion between populations whose ancestors lived indifferent environmental settings. Human populations exhibit similar climatic variation patterns to other large-bodiedmammals, following Bergmann's rule, which states that individuals in cold climates will tend to be larger than onesin warm climates, and Allen's rule, which states that individuals in cold climates will tend to have shorter, stubbierlimbs than those in warm climates.On a micro evolutionary level, anthropologists use anthropometric variation to reconstruct small-scale populationhistory. For instance, John Relethford's studies of early twentieth-century anthropometric data from Ireland showthat the geographical patterning of body proportions still exhibits traces of the invasions by the English and Norsecenturies ago.Outside academia, scientists working for private companies and government agencies conduct anthropometricstudies to determine what range of sizes clothing and other items need to be manufactured in. A basicallyanthropometric division of body types into the categories endomorphic, ectomorphic and mesomorphic derived fromSheldon's somatotype theories is today popular among people doing weight training. Measurements of the foot areused in the manufacture and sale of footwear; measurement devices may be used to either directly determine a retailshoe size (e.g. Brannock Device) or determine the detailed dimensions of the foot for custom manufacture (e.g.ALINEr).The US Military has conducted over 40 anthropometric surveys of U.S. Military personnel between 1945 and 1988,including the 1988 Army Anthropometric Survey (ANSUR) of men and women with its 240 measures. Statisticaldata from these surveys, which encompassed over 75,000 individuals, can be found in [3].

Anthropometry 26

Today people are performing anthropometry with three-dimensional scanners. The subject has a three-dimensionalscan taken of their body, and the anthropometrist extracts measurements from the scan rather than directly from theindividual. This is beneficial for the anthropometrist in that they can use this scan to extract any measurement at anytime and the individual does not have to wait for each measurement to be taken separately.In 2001 the UK conducted the largest sizing survey using scanners up to date. Since then there have been severalnational surveys which have followed in the UK's pioneering steps, notably these are SizeUSA, SizeMexico & SizeThailand, the latter are still ongoing. Size UK showed that the nation had got taller and heavier, but not as much asmany had expected. Since 1951 when the last women's survey had taken place the average weight for women hadgone up from 62 to 65 kg.A global collaborative study to examine the uses of three-dimensional scanners for health care was launched inMarch 2007. The Body Benchmark Study [4] will investigate the use of three-dimensional scanners to calculatevolumes and segmental volumes of an individual body scan. The aim is to establish whether The Body VolumeIndex has the potential to be used as a long-term computer based anthropometric measurement for health care. Moreconventional anthropometric measurements also have uses in medical anthropology and epidemiology, for examplein helping to determine the relationship between various body measurements (height, weight, percentage body fat,etc.) and medical outcomes.

See also• Craniometry• Criminology• Dermatoglyphics• Digit ratio• Ergonomics• Fingerprinting• Genetic fingerprinting• Human factors• Human height• Human weight• Osteometry• Phrenology• Somatotypology• Kinanthropometry• Typology (anthropology)

Notes and references[1] "From Savage to Negro" (1998) Lee D. Baker p.14[2] "The Mismeasure of Man" Stephen Jay Gould (1981)[3] http:/ / assist. daps. dla. mil/ docimages/ 0000/ 40/ 29/ 54083. PD0[4] http:/ / www. bodybenchmark. org

• (http:/ / assist. daps. dla. mil/ docimages/ 0000/ 40/ 29/ 54083. PD0), Anthropometry of US Military Personnel(1991)

• ISO 7250: Basic human body measurements for technological design, International Organization forStandardization, 1998.

• ISO 8559: Garment construction and anthropometric surveys — Body dimensions, International Organization forStandardization, 1989.

Anthropometry 27

• ISO 15535: General requirements for establishing anthropometric databases, International Organization forStandardization, 2000.

• ISO 15537: Principles for selecting and using test persons for testing anthropometric aspects of industrialproducts and designs, International Organization for Standardization, 2003.

• ISO 20685: 3-D scanning methodologies for internationally compatible anthropometric databases, InternationalOrganization for Standardization, 2005.

Historic references• Lombroso, Antropometria di 400 delinquenti (1872)• Roberts, Manual of Anthropometry (1878)• Ferri, Studi comparati di antropometria (2 vols., 1881-1882)• Lombroso, Rughe anomale speciali ai criminali (1890)• Bertillon, Instructions signalétiques pour l'identification anthropométrique (1893)• Livi, Anthropometria (Milan, 1900)• Fürst, Indextabellen zum anthropometrischen Gebrauch (Jena, 1902)• Report of Home Office Committee on the Best Means of Identifying Habitual Criminals (1893-1894)In art Yves Klein termed anthropometries his performance paintings where he covered nude women with paint, andused their bodies as paintbrushes.

Resources• Pheasant, Stephen (1986). Bodyspace : anthropometry, ergonomics, and design. London; Philadelphia: Taylor &

Francis. ISBN 0850663520. (A classic review of human body sizes.)

External links• Anthropometrics in design resources (http:/ / www. humanics-es. com/ recc-ergonomics.

htm#humanfactorsergonomics)• ANTHROPOMETRY AND BIOMECHANICS according to NASA (http:/ / msis. jsc. nasa. gov/ sections/

section03. htm)• Anthropometry data at faculty of Industrial Design Engineering at Delft University of Technology (http:/ / www.

dined. nl)• Forensic Anthropometry (http:/ / www. ispub. com/ ostia/ index. php?xmlFilePath=journals/ ijfs/ vol2n1/ forensic.

xml) Anthropometry in Forensics• (http:/ / www. dtic. mil/ dticasd/ anthro. html) DoD and US Government Anthropometry• Anthropometric Findings: (http:/ / www. udeworld. com/ anthropometrics. html) The Anthropometrics of

Disability, Space Requirements for Wheeled Mobility, Standards and Anthropometry for Wheeled Mobility

Rohmert's law 28

Rohmert's lawWidely used in the human factors and ergonomics field, Rohmert's law states that the maximum force one's musclescan exert decreases exponentially from the time one begins continuously exerting the said force. It is commonly usedto calculate "maximum holding time" for any particular task.Maximum force decays exponentially due to the amount of energy (in the form of oxygen and ATP) the body is ableto supply to the muscles. The circulatory systems keeps muscles flooded in nutrients at all times, so that muscleshave a supply of fuel ready to burn at any given moment. A task requiring maximum force burns a large amount ofthose nutrients at the onset of the task; the circulatory system is then unable to replenish the nutrients at a rate fastenough to maintain maximum force for long. As a result, the maximum force the muscle is capable of producing islimited by the bottleneck in nutrient availability, and decreases exponentially.Imagine a theoretical arm wrestling match with two perfectly matched opponents, each exactly as strong as eachother. They both begin the match by exerting maximum force on each other's hands, but very soon, their arms getfatigued and the actual force being exerted on each others' hands drops off quickly. They are still exerting as muchforce as they can, but their muscles are burning energy faster than can be replenished, and their maximum force isdecreasing exponentially. Eventually their arms are completely fatigued; they are basically just holding hands andapplying what little force their muscles can muster, wondering when the other will give up.While Rohmert's law applies to maximum force, the inverse is true as well; the less force one is asked to exert, thelonger one will be able to exert that force before their muscles become fatigued. If one is asked to exert zero force,they can theoretically hold the position indefinitely.Rohmert's law has been found to be true across all humans. While everyone has a different initial maximum forcethey can apply, their maximum force will decrease according to the same exponential curve as everyone else.

Experience designExperience design (XD) is the practice of designing products, processes, services, events, and environments with afocus placed on the quality of the user experience and culturally relevant solutions, with less emphasis placed onincreasing and improving functionality of the design.[1] An emerging discipline, experience design attempts to drawfrom many sources including cognitive psychology and perceptual psychology, linguistics, cognitive science,architecture and environmental design, haptics, hazard analysis, product design, information design, informationarchitecture, ethnography, brand management, interaction design, service design, storytelling, heuristics, and designthinking.

Commercial contextIn its commercial context, experience design is driven by consideration of the moments of engagement, ortouchpoints, between people and brands, and the ideas, emotions, and memories that these moments create.Commercial experience design is also known as experiential marketing, customer experience design, and brandexperience. Experience designers are often employed to identify existing touchpoints and create new ones, and thento score the arrangement of these touchpoints so that they produce the desired outcome.

Experience design 29

Broader contextIn the broader environmental context, there is far less formal attention given to the design of the experiencedenvironment, physical and virtual — but though it's unnoticed, experience design is taking place. Ronald Jones,describes the practice as working across disciplines, often furthest from their own creating a relevant integrationbetween concepts, methods and theories. Experience designers design experiences over time with real andmeasurable consequences; time is their medium. According to Jones, the mission of Experience Design is "topersuade, stimulate, inform, envision, entertain, and forecast events, influencing meaning and modifying humanbehavior."[2]

Within companies, experience design can refer not just to the experience of customers, but to that of employees aswell. Anyone who is exposed to the space either physically, digitally, or second hand (web, media, family member,friend) may be considered in the application of XD. This includes staff, vendors, patients, visiting professionals,families, media professionals and contractors.

Focus debatedThere is a debate occurring in the experience design community regarding its focus, provoked in part by designscholar and practitioner, Don Norman. Norman claims that, when designers describe people only as customers,consumers, and users, designers risk diminishing their ability to do good design.[3] Given that experience is so totallyan affective, subjective, and personal process — not an abstract — it would be ironic, it's been argued, forexperience designers, when designing experiences, to approach people merely as objects of commerce or cogs in amachine. Experience design, perhaps more than other forms of design, is transactive and transformative: everyexperience designer is an experiencer; and every experiencer, via his or her reactions, a designer of experience inturn. While commercial contexts often describe people as "customers, consumers, or users," this and non-commercialcontexts might use the words "audience, people, and participants." In either case, for conscientious experiencedesigners, this is merely a semantic difference.

Multiple dimensionsExperience design is not driven by a single design discipline. Instead, it requires a cross-discipline perspective thatconsiders multiple aspects of the brand/business/environment/experience from product, packaging and retailenvironment to the clothing and attitude of employees. Experience design seeks to develop the experience of aproduct, service, or event along any or all of the following dimensions:[4]

• Duration (Initiation, Immersion, Conclusion, and Continuation)• Intensity (Reflex, Habit, Engagement)• Breadth (Products, Services, Brands, Nomenclatures, Channels/Environment/Promotion, and Price)• Interaction (Passive < > Active < > Interactive)• Triggers (All Human Senses, Concepts, and Symbols)• Significance (Meaning, Status, Emotion, Price, and Function)While it's unnecessary (or even inappropriate) for all experiences to be developed highly across all of thesedimensions, the more in-depth and consistently a product or service is developed across them — the more responsivean offering is to a group's or individual's needs and desires (e.g., a customer) it's likely to be. Enhancing theaffordance of a product or service, its interface with people, is key to commercial experience design.

Experience design 30

See also• Human factors• Industrial design• Information Architecture• Interaction design• Interdisciplinary• Marketing• Transdisciplinary• Usability• User experience design• User interface design

References[1] Aarts, Emile H. L.; Stefano Marzano (2003). The New Everyday: Views on Ambient Intelligence. 010 Publishers. p. 46.

ISBN 9789064505027.[2] "Ronald Jones" (http:/ / varutstallning08. konstfack. se/ interdisciplinary-studies/ ronald-jones. html). Konstfack Vårutställning 2008. .

Retrieved 2008-10-03.[3] "Words Matter. Talk About People: Not Customers, Not Consumers, Not Users" (http:/ / jnd. org/ dn. mss/

words_matter_talk_about_people_not_customers_not_consumers_not_users. html). Don Norman's jnd website. . Retrieved 2008-10-03.[4] Steve Diller, Nathan Shedroff, Darrel Rhea (2005): Making Meaning: How Successful Businesses Deliver Meaningful Customer Experiences.

New Riders Press ISBN 0321374096

Industrial design

An iPod, an industrially designed product.

KitchenAid 5 qt. Stand Mixer, designed in 1937by Egmont Arens, remains very successful today

Industrial design is a discipline whereby the aesthetics, ergonomicsand usability of mass-produced products may be improved formarketability and production. The main objective is to create andexecute design solutions towards problems of form, usability, userergonomics, engineering, marketing, brand development and sales.

The term "industrial design" is often attributed to the artist JosephClaude Sinel in 1919 (although he himself denied it in later interviews)but the specialization predates that by at least a decade. Its origins layin the industrialization of consumer products, and the increasingly needof architecture to focus on “small” problems of the form. For instancethe Deutscher Werkbund, founded in 1907 and a precursor to theBauhaus, was a state-sponsored effort to integrate traditional crafts andindustrial mass-production techniques, to put Germany on acompetitive footing with England and the United States.

Industrial design 31

Definition of industrial design

Western Electric model 302 Telephone, foundalmost universally in the United States from 1937until the introduction of touch-tone dialing, as the

Family's life was extended into the 1960s[1]

General The objective of this area is to study both function and form,and the relation between user - product as it happens in any otherarchitecture area, being the only difference, that here the professionalsthat participate in the process are all specialized in small scale design,rather than in other massive colossal equipments like buildings orships. Architects do not design the gears or motors that make machinesmove, or the circuits that control the movement (that task is usuallyattributed to engineers also specialized in industrial design), but theycan affect technical aspects through usability design and formrelationships. And usually, they partner a whole of other professionalslike marketers, to identify and fulfill needs, wants and expectations,lawyer, etc.

In Depth "Industrial Design (ID) is the professional service of creatingand developing concepts and specifications that optimize the function,value and appearance of products and systems for the mutual benefit of both user and manufacturer" in a small scaledesign [2] .

Design, itself, is often difficult to define to non-designers because the meaning accepted by the design community isnot one made of words. Instead, the definition is created as a result of acquiring a critical framework for the analysisand creation of artifacts. One of the many accepted (but intentionally unspecific) definitions of design originatesfrom Carnegie Mellon's School of Design, "Design is the process of taking something from its existing state andmoving it to a preferred state." [3] This applies to new artifacts, whose existing state is undefined, and previouslycreated artifacts, whose state stands to be improved.According to the Chartered Society of Designers, design is a force that delivers innovation that in turn has exploitedcreativity [4] . Their design framework known as the Design Genetic Matrix determines a set of competences in 4 keygenes that are identified to define the make up of designers and communicate to a wide audience what they do.Within these genes the designer demonstrates the core competences of a designer and specific competencesdetermine the designer as an 'industrial designer'. This is normally within the context of delivering innovation in theform of a three dimensional product that is produced in quantity. However the definition also extends to productsthat have been produced using an industrial process.According to the ICSID (International Council of Societies of Industrial Design), "Design is a creative activitywhose aim is to establish the multi-faceted qualities of objects, processes, services and their systems in wholelife-cycles. Therefore, design is the central factor of innovative humanization of technologies and the crucial factorof cultural and economic exchange."[5]

Industrial design 32

Process of design

A Fender Stratocaster with sunburst finish, one ofthe most widely recognized electric guitars in the

world.

Model 1300 Volkswagen Beetle

Although the process of design may be considered 'creative', manyanalytical processes also take place. In fact, many industrial designersoften use various design methodologies in their creative process. Someof the processes that are commonly used are user research, sketching,comparative product research, model making, prototyping and testing.These processes can be chronological, or as best defined by thedesigners and/or other team members. Industrial designers often utilize3D software, computer-aided industrial design and CAD programs tomove from concept to production. Product characteristics specified bythe industrial designer may include the overall form of the object, thelocation of details with respect to one another, colors, texture, sounds,and aspects concerning the use of the product ergonomics.Additionally the industrial designer may specify aspects concerning theproduction process, choice of materials and the way the product ispresented to the consumer at the point of sale. The use of industrialdesigners in a product development process may lead to added valuesby improved usability, lowered production costs and more appealingproducts. However, some classic industrial designs are considered asmuch works of art as works of engineering: the iPod, the Jeep, theFender Stratocaster, the Coke bottle, and the VW Beetle are frequentlycited examples.

Design also has a focus on technical concepts, products and processes.In addition to considering aesthetics, usability, and ergonomics, it canalso encompass the engineering of objects, usefulness as well asusability, market placement, and other concerns such as seduction,psychology, desire, and the emotional attachment of the user to theobject. These values and accompanying aspects on which industrial design is based can vary, both between differentschools of thought and among practicing designers.

Product design and industrial design can overlap into the fields of user interface design, information design andinteraction design. Various schools of architecture may specialize in one of these aspects, ranging from pure artcolleges (product styling) to mixed programs of engineering and design, to related disciplines like exhibit design andinterior/exterior design, to schools where aesthetic design is almost completely subordinated to concerns of functionand ergonomics of use (the so-called functionalist school , like the example of Bauhaus).[6]

Industrial design rightsIndustrial design rights are intellectual property rights that make exclusive the visual design of objects that are notpurely utilitarian. An industrial design consists of the creation of a shape, configuration or composition of pattern orcolor, or combination of pattern and color in three dimensional form containing aesthetic value. An industrial designcan be a two- or three-dimensional pattern used to produce a product, industrial commodity or handicraft. Under theHague Agreement Concerning the International Deposit of Industrial Designs, a WIPO-administered treaty, aprocedure for an international registration exists. An applicant can file for a single international deposit with WIPOor with the national office in a country party to the treaty. The design will then be protected in as many membercountries of the treaty as desired.

Industrial design 33

Notable industrial designersA number of industrial designers have made such a significant impact on culture and daily life that they haveattained a level of notability beyond that of an average designer. Alvar Aalto, renowned as an architect, alsodesigned a significant number of household items, such as chairs, stools, lamps, a tea-cart, and vases. RaymondLoewy was a prolific American designer who is responsible for the Royal Dutch Shell corporate logo, the originalBP logo (in use until 2000), the PRR S1 steam locomotive, the Studebaker Starlight (including the later iconicbulletnose), as well as Schick electric razors, Electrolux refrigerators, short-wave radios, Le Creuset French ovens,and a complete line of modern furniture, among many other items. Richard A. Teague, who spent most of his careerwith the American Motor Company, originated the concept of using interchangable body panels so as to create awide array of different vehicles using the same stampings. He was responsible for such unique automotive designs asthe Pacer, Gremlin, Matador coupe, Jeep Cherokee, and the complete interior of the Eagle Premier. Charles and RayEames were most famous for their unique furniture design, such as the Eames Lounge Chair Wood and EamesLounge Chair.

See also• Architecture• Designer• Australian International Design Awards• Automotive design• Product design• Interaction design• Core77• Industrial Designers Society of America• Creative engineering• Emotional Design by Donald Norman• Environmental design• Experience design• Hague system• Product development• Rapid prototyping• WikID

NotesA. ^ See his autobiography Against The Odds, Pub Thomson 2002[7]

References[1] (http:/ / www. paul-f. com/ we300typ. htm) - Western Electric 300-series Telephone Types[2] (http:/ / www. idsa. org/ absolutenm/ templates/ ?a=89) - Industrial Designers Society of America[3] (http:/ / design. cmu. edu/ ) - Carnegie Mellon's School of Design[4] (http:/ / www. csd. org. uk/ ) - Chartered Society of Designers[5] ICSID.ORG (http:/ / www. icsid. org/ about/ about/ articles31. htm) - Definition of Design.[6] Pulos, Arthur J., The American Design Adventure 1940-1975, Cambridge, Mass:MIT Press (1988), p. 249 (ISBN 9780262161060)[7] Dyson, James (1997). Against the odds: An autobiography. London: Orion Business. ISBN 9780752809816. OCLC 38066046.

Objects of Desire: Design and Society Since 1750. Adrian Forty, Thames Hudson, May 1992. ISBN978-0500274125

Industrial design 34

External links• International Council of Societies of Industrial Design (http:/ / www. icsid. org/ )• U.S. Department of Labor's Handbook: Commercial and Industrial Designers (http:/ / www. bls. gov/ oco/

ocos290. htm)• Doodles, Drafts and Designs: Industrial Drawings from the Smithsonian (http:/ / www. sil. si. edu/ exhibitions/

doodles/ ) (2004) Smithsonian Institution Libraries

Design for All (design philosophy)Design for All (DfA) is a design philosophy targeting the use of products, services and systems by as many peopleas possible without the need for adaptation. Design for All is design for human diversity, social inclusion andequality (EIDD Stockholm Declaration, 2004).According to the European Commission, it "encourages manufacturers and service providers to produce newtechnologies for everyone: technologies that are suitable for the elderly and people with disabilities, as much as theteenage techno wizard."[1]

Closely related to the concepts of Inclusive Design or Universal Design,[2] the origin of Design for All lies in thefield of barrier free accessibility for people with disabilities, where it has been recognised that this provides benefitsto a much larger population.

BackgroundDesign for All has been highlighted in Europe by the European Commission in seeking a more user-friendly societyin Europe.[1] Design for All is about ensuring that environments, products, services and interfaces work for people ofall ages and abilities in different situations and under various circumstances.Design for All has become a mainstream issue because of the ageing of the population and its increasinglymultiethnic composition. It follows a market approach and can reach out to a broader market. Easy-to-use,accessible, affordable products and services improve the quality of life of all citizens. Design for All permits accessto the built environment, access to services and user-friendly products which are not just a quality factor but anecessity for many ageing or disabled persons. Including Design for All early in the design process is morecost-effective than making alterations after solutions are already in the market. This is best achieved by identifyingand involving users ("stakeholders") in the decision-making processes that lead to drawing up the design brief andeducating public and private sector decision-makers about the benefits to be gained from making coherent use ofDesign (for All) in a wide range of socio-economic situations.

Examples of Design for AllThe following examples of Designs for All were presented in the book Diseños para Todos/Designs for Allpublished in 2008 by Optimastudio with the support of Spain's Ministry of Education, Social Affairs and Sports(IMSERSO) and CEAPAT:[3]

• Q-Drums[4]

• Velcro• Electric Toothbrush• Tactile paving• Automatic door• Low-floor bus• Trolley case

Design for All (design philosophy) 35

• Flexible drinking straw• Google• Audiobook

Design for All in Information and Communication Technology (ICT)Design for All criteria are aimed at ensuring that everyone can participate in the Information Society. The EuropeanUnion refers to this under the terms eInclusion and eAccessibility. A three-way approach is proposed: goods whichcan be accessed by nearly all potential users without modification or, failing that, products being easy to adaptaccording to different needs, or using standardised interfaces that can be accessed simply by using assistivetechnology. To this end, manufacturers and service providers, especially, but not exclusively, in the Information andCommunication Technologies (ICT), produce new technologies, products, services and applications for everyone.[1]

European networksIn Europe, people have joined in networks to promote and develop Design for All:• The European Design for All eAccessibility Network (EDeAN)[5] was lauched under the lead of the European

Commission and the European Member States in 2002. It fosters Design for All for eInclusion, that is, creating aninformation society for all. It has national contact centres (NCCs) in almost all EU countries and more than 160network members in national networks.

• EIDD - Design for All Europe is a 100% self-financed European organisation that covers the entire area of theoryand practice of Design for All, from the built environment and tangible products to communication, service andsystem design. Originally set up in 1993 as the European Institute for Design and Disability (EIDD),[6] to enhancethe quality of life through Design for All, it changed its name in 2006 to bring it into line with its core business.EIDD - Design for All Europe disseminates the application of Design for All to business and administrationcommunities previously unaware of its benefits and currently (2009) has active member organisations in 22European countries.

See also• Accessibility• Accessible tourism• Assistive technology• Bobby (software)• Disability• Knowbility• Usability• Visitability

Design for All (design philosophy) 36

References[1] European Commission: Design for All (DfA) (http:/ / ec. europa. eu/ information_society/ activities/ einclusion/ policy/ accessibility/ dfa/

index_en. htm).[2] The UK Council for Museums, Archives and Libraries (http:/ / www. accessibletourism. org/ resources/

uk_museumsand-galleries_disability_directory_pdf_6877. pdf)[3] Feo, Roberto & Hurtado, Rosario & Optimastudio Diseños para Todos/Designs for All Madrid 2008, ISBN 978-84-691-3870-0 (http:/ / www.

optimastudio. com/ disenosparatodos) Downloadable free version of Designs for All[4] Q-Drums (http:/ / www. qdrum. co. za/ )[5] European Design for All eAccessibility Network (http:/ / www. edean. org/ )[6] EIDD - Design for All Europe (http:/ / www. designforalleurope. org/ About-EIDD/ )

Human–computer interaction

A mouse is a pointing device that functions by detectingtwo-dimensional motion relative to its supporting surface.

Human–computer interaction (HCI) is the study ofinteraction between people (users) and computers. It isoften regarded as the intersection of computer science,behavioral sciences, design and several other fields ofstudy. Interaction between users and computers occursat the user interface (or simply interface), whichincludes both software and hardware; for example,characters or objects displayed by software on apersonal computer's monitor, input received from usersvia hardware peripherals such as keyboards and mice,and other user interactions with large-scalecomputerized systems such as aircraft and powerplants. The Association for Computing Machinerydefines human-computer interaction as "a disciplineconcerned with the design, evaluation andimplementation of interactive computing systems forhuman use and with the study of major phenomenasurrounding them."[1] An important facet of HCI is the securing of user satisfaction (see Computer user satisfaction).

Because human-computer interaction studies a human and a machine in conjunction, it draws from supportingknowledge on both the machine and the human side. On the machine side, techniques in computer graphics,operating systems, programming languages, and development environments are relevant. On the human side,communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology,and human factors are relevant. Engineering and design methods are also relevant. Due to the multidisciplinarynature of HCI, people with different backgrounds contribute to its success. HCI is also sometimes referred to asman–machine interaction (MMI) or computer–human interaction (CHI).

Attention to human-machine interaction is important, because poorly designed human-machine interfaces can lead tomany unexpected problems. A classic example of this is the Three Mile Island accident where investigationsconcluded that the design of the human-machine interface was at least partially responsible for the disaster.[2]

Similarly, accidents in aviation have resulted from manufacturers' decisions to use non-standard flight instrumentand/or throttle quadrant layouts: even though the new designs were proposed to be superior in regards to basichuman-machine interaction, pilots had already ingrained the "standard" layout and thus the conceptually good ideaactually had undesirable results.

Human–computer interaction 37

GoalsA basic goal of HCI is to improve the interactions between users and computers by making computers more usableand receptive to the user's needs. Specifically, HCI is concerned with:• methodologies and processes for designing interfaces (i.e., given a task and a class of users, design the best

possible interface within given constraints, optimizing for a desired property such as learning ability or efficiencyof use)

• methods for implementing interfaces (e.g. software toolkits and libraries; efficient algorithms)• techniques for evaluating and comparing interfaces• developing new interfaces and interaction techniques• developing descriptive and predictive models and theories of interactionA long term goal of HCI is to design systems that minimize the barrier between the human's cognitive model of whatthey want to accomplish and the computer's understanding of the user's task.Professional practitioners in HCI are usually designers concerned with the practical application of designmethodologies to real-world problems. Their work often revolves around designing graphical user interfaces andweb interfaces.Researchers in HCI are interested in developing new design methodologies, experimenting with new hardwaredevices, prototyping new software systems, exploring new paradigms for interaction, and developing models andtheories of interaction.

Differences with related fieldsHCI differs from human factors in that with HCI the focus is more on users working specifically with computers,rather than other kinds of machines or designed artifacts. There is also a focus in HCI on how to implement thecomputer software and hardware mechanisms to support human-computer interaction. Thus, human factors is abroader term; HCI could be described as the human factors of computers - although some experts try to differentiatethese areas.According to some experts, HCI also differs from ergonomics in that there is less of a focus on repetitivework-oriented tasks and procedures, and much less emphasis on physical stress and the physical form or industrialdesign of the user interface, such as keyboards and mice. However, this does not take a full account of ergonomics,the oldest areas of which were mentioned above, but which more recently has gained a much broader focus(equivalent to human factors). Cognitive ergonomics, for example, is a part of ergonomics, of which softwareergonomics (an older term, essentially the same as HCI) is a part.[3]

Three areas of study have substantial overlap with HCI even as the focus of inquiry shifts. In the study of personalinformation management (PIM), human interactions with the computer are placed in a larger informational context -people may work with many forms of information, some computer-based, many not (e.g., whiteboards, notebooks,sticky notes, refrigerator magnets) in order to understand and effect desired changes in their world. In computersupported cooperative work (CSCW), emphasis is placed on the use of computing systems in support of thecollaborative work of a group of people. The principles of human interaction management (HIM) extend the scope ofCSCW to an organizational level and can be implemented without use of computer systems.

Human–computer interaction 38

Design principlesWhen evaluating a current user interface, or designing a new user interface, it is important to keep in mind thefollowing experimental design principles:• Early focus on user(s) and task(s): Establish how many users are needed to perform the task(s) and determine who

the appropriate users should be; someone that has never used the interface, and will not use the interface in thefuture, is most likely not a valid user. In addition, define the task(s) the users will be performing and how oftenthe task(s) need to be performed.

• Empirical measurement: Test the interface early on with real users who come in contact with the interface on aneveryday basis. Keep in mind that results may be altered if the performance level of the user is not an accuratedepiction of the real human-computer interaction. Establish quantitative usability specifics such as: the number ofusers performing the task(s), the time to complete the task(s), and the number of errors made during the task(s).

• Iterative design: After determining the users, tasks, and empirical measurements to include, perform the followingiterative design steps:

1. Design the user interface2. Test3. Analyze results4. RepeatRepeat the iterative design process until a sensible, user-friendly interface is created.[4]

Design methodologiesA number of diverse methodologies outlining techniques for human–computer interaction design have emergedsince the rise of the field in the 1980s. Most design methodologies stem from a model for how users, designers, andtechnical systems interact. Early methodologies, for example, treated users' cognitive processes as predictable andquantifiable and encouraged design practitioners to look to cognitive science results in areas such as memory andattention when designing user interfaces. Modern models tend to focus on a constant feedback and conversationbetween users, designers, and engineers and push for technical systems to be wrapped around the types ofexperiences users want to have, rather than wrapping user experience around a completed system.• User-centered design: user-centered design (UCD) is a modern, widely practiced design philosophy rooted in the

idea that users must take center-stage in the design of any computer system. Users, designers and technicalpractitioners work together to articulate the wants, needs and limitations of the user and create a system thataddresses these elements. Often, user-centered design projects are informed by ethnographic studies of theenvironments in which users will be interacting with the system. This practice is similar but not identical toParticipatory Design, which emphasizes the possibility for end-users to contribute actively through shared designsessions and workshops.

• Principles of User Interface Design: these are seven principles that may be considered at any time during thedesign of a user interface in any order, namely Tolerance, Simplicity, Visibility, Affordance, Consistency,Structure and Feedback.[5]

• See List of human-computer interaction topics#Interface design methods for more

Human–computer interaction 39

Display designsDisplays are human-made artifacts designed to support the perception of relevant system variables and to facilitatefurther processing of that information. Before a display is designed, the task that the display is intended to supportmust be defined (e.g. navigating, controlling, decision making, learning, entertaining, etc.). A user or operator mustbe able to process whatever information that a system generates and displays; therefore, the information must bedisplayed according to principles in a manner that will support perception, situation awareness, and understanding.THIRTEEN PRINCIPLES OF DISPLAY DESIGN[6]

These principles of human perception and information processing can be utilized to create an effective displaydesign. A reduction in errors, a reduction in required training time, an increase in efficiency, and an increase in usersatisfaction are a few of the many potential benefits that can be achieved through utilization of these principles.Certain principles may not be applicable to different displays or situations. Some principles may seem to beconflicting, and there is no simple solution to say that one principle is more important than another. The principlesmay be tailored to a specific design or situation. Striking a functional balance among the principles is critical for aneffective design. [7]

Perceptual Principles

1. Make displays legible (or audible)

A display’s legibility is critical and necessary for designing a usable display. If the characters or objects beingdisplayed cannot be discernible, then the operator cannot effectively make use of them.2. Avoid absolute judgment limits

Do not ask the user to determine the level of a variable on the basis of a single sensory variable (e.g. color, size,loudness). These sensory variables can contain many possible levels.3. Top-down processing

Signals are likely perceived and interpreted in accordance with what is expected based on a user’s past experience. Ifa signal is presented contrary to the user’s expectation, more physical evidence of that signal may need to bepresented to assure that it is understood correctly.4. Redundancy gain

If a signal is presented more than once, it is more likely that it will be understood correctly. This can be done bypresenting the signal in alternative physical forms (e.g. color and shape, voice and print, etc.), as redundancy doesnot imply repetition. A traffic light is a good example of redundancy, as color and position are redundant.5. Similarity causes confusion: Use discriminable elements

Signals that appear to be similar will likely be confused. The ratio of similar features to different features causessignals to be similar. For example, A423B9 is more similar to A423B8 than 92 is to 93. Unnecessary similar featuresshould be removed and dissimilar features should be highlighted.Mental Model Principles

6. Principle of pictorial realism

A display should look like the variable that it represents (e.g. high temperature on a thermometer shown as a highervertical level). If there are multiple elements, they can be configured in a manner that looks like it would in therepresented environment.7. Principle of the moving part

Moving elements should move in a pattern and direction compatible with the user’s mental model of how it actuallymoves in the system. For example, the moving element on an altimeter should move upward with increasing altitude.Principles Based on Attention

8. Minimizing information access cost

Human–computer interaction 40

When the user’s attention is diverted from one location to another to access necessary information, there is anassociated cost in time or effort. A display design should minimize this cost by allowing for frequently accessedsources to be located at the nearest possible position. However, adequate legibility should not be sacrificed to reducethis cost.9. Proximity compatibility principle

Divided attention between two information sources may be necessary for the completion of one task. These sourcesmust be mentally integrated and are defined to have close mental proximity. Information access costs should be low,which can be achieved in many ways (e.g. close proximity, linkage by common colors, patterns, shapes, etc.).However, close display proximity can be harmful by causing too much clutter.10. Principle of multiple resources

A user can more easily process information across different resources. For example, visual and auditory informationcan be presented simultaneously rather than presenting all visual or all auditory information.Memory Principles

11. Replace memory with visual information: knowledge in the world

A user should not need to retain important information solely in working memory or to retrieve it from long-termmemory. A menu, checklist, or another display can aid the user by easing the use of their memory. However, the useof memory may sometimes benefit the user by eliminating the need to reference some type of knowledge in theworld (e.g. an expert computer operator would rather use direct commands from memory than refer to a manual).The use of knowledge in a user’s head and knowledge in the world must be balanced for an effective design.12. Principle of predictive aiding

Proactive actions are usually more effective than reactive actions. A display should attempt to eliminateresource-demanding cognitive tasks and replace them with simpler perceptual tasks to reduce the use of the user’smental resources. This will allow the user to not only focus on current conditions, but also think about possiblefuture conditions. An example of a predictive aid is a road sign displaying the distance from a certain destination.13. Principle of consistency

Old habits from other displays will easily transfer to support processing of new displays if they are designed in aconsistent manner. A user’s long-term memory will trigger actions that are expected to be appropriate. A design mustaccept this fact and utilize consistency among different displays.

Human–computer interfaceThe human–computer interface can be described as the point of communication between the human user and thecomputer. The flow of information between the human and computer is defined as the loop of interaction. The loopof interaction has several aspects to it including:• Task Environment: The conditions and goals set upon the user.• Machine Environment: The environment that the computer is connected to, i.e a laptop in a college student's

dorm room.• Areas of the Interface: Non-overlapping areas involve processes of the human and computer not pertaining to

their interaction. Meanwhile, the overlapping areas only concern themselves with the processes pertaining to theirinteraction.

• Input Flow: The flow of information that begins in the task environment, when the user has some task thatrequires using their computer.

• Output: The flow of information that originates in the machine environment.• Feedback: Loops through the interface that evaluate, moderate, and confirm processes as they pass from the

human through the interface to the computer and back.

Human–computer interaction 41

Academic conferencesOne of the top academic conferences for new research in human-computer interaction, especially within computerscience, is the annually held ACM's Conference on Human Factors in Computing Systems, usually referred to by itsshort name CHI (pronounced kai, or khai). CHI is organized by ACM SIGCHI [8] Special Interest Group onComputer–Human Interaction. CHI is a large, highly competitive conference, with thousands of attendants, and isquite broad in scope.There are also dozens of other smaller, regional or specialized HCI-related conferences held around the world eachyear, the most important of which include (see also [9]):

Special purpose

• ASSETS [10]: ACM International Conference on Computers and Accessibility• CSCW [11]: ACM conference on Computer Supported Cooperative Work.• DIS [12]: ACM conference on Designing Interactive Systems.• ECSCW [13]: European Conference on Computer-Supported Cooperative Work. Every second year.• GROUP [14]: ACM conference on Supporting Group Work.• HRI [15]: ACM/IEEE International Conference on Human-robot interaction.• ICMI [16]: International Conference on Multimodal Interfaces.• ITS [17]: ACM conference on Interactive Tabletops and Surfaces.• IUI [18]: International Conference on Intelligent User Interfaces.• MobileHCI: International Conference on Human-Computer Interaction with Mobile Devices and Services.• NIME [19]: International Conference on New Interfaces for Musical Expression.• Ubicomp [20]: International Conference on Ubiquitous computing• UIST [21]: ACM Symposium on User Interface Software and Technology.

Regional and general HCI

• INTERACT [22]: IFIP TC13 International Conference on Human-Computer Interaction. Biennial, alternatingyears with AVI.

• AVI [23]: International Working Conference on Advanced Visual Interfaces. Held biennially in Italy, alternatingyears with INTERACT.

• MexIHC [24]: MexIHC - Mexican Workshops on Human-Computer Interaction• HCI International [25]: International Conference on Human-Computer Interaction.• ACHI [26]: International Conferences on Advances in Human-Computer Interaction.• HCI [27]: British HCI Conference.• OZCHI [28]: Australasian HCI Conference.• IHM [29]: Annual French-speaking HCI Conference.• Graphics Interface [30]: Annual Canadian computer graphics and HCI conference. The oldest regularly scheduled

conference for graphics and human-computer interaction.• NordiCHI [31]: Nordic Conference on Human-Computer Interaction. Biennial.

Human–computer interaction 42

See also• Usability• Human factors / Ergonomics• Interaction design• Full list of HCI-related topics

Further reading• Academic overview of the field by many authors:

• Andrew Sears and Julie A. Jacko (Eds.). (2007). Handbook for Human Computer Interaction (2nd Edition).CRC Press. ISBN 0-8058-5870-9

• Julie A. Jacko and Andrew Sears (Eds.). (2003). Handbook for Human Computer Interaction. Mahwah:Lawrence Erlbaum & Associates. ISBN 0-8058-4468-6

• Historically important classic:• Stuart K. Card, Thomas P. Moran, Allen Newell (1983): The Psychology of Human–Computer Interaction.

Erlbaum, Hillsdale 1983 ISBN 0-89859-243-7• Overview of history of the field:

• Jonathan Grudin: A moving target: The evolution of human–computer interaction. In Andrew Sears and JulieA. Jacko (Eds.). (2007). Handbook for Human Computer Interaction (2nd Edition). CRC Press. ISBN0-8058-5870-9

• Brad Myers: A brief history of human–computer interaction technology. Interactions 5(2):44–54, 1998, ISSN1072–5520 ACM Press. http:/ / doi. acm. org/ 10. 1145/ 274430. 274436

• John M. Carroll: Human Computer Interaction: History and Status. [32] Encyclopedia Entry atInteraction-Design.org

• Academic journals:• ACM Transactions on Computer-Human Interaction• Behaviour & Information Technology [33]• International Journal of Human-Computer Interaction• Human-Computer Interaction [34] [35]

• Collection of key papers:• Ronald M. Baecker, Jonathan Grudin, William A. S. Buxton, Saul Greenberg (Eds.) (1995): Readings in

human–computer interaction. Toward the Year 2000. 2. ed. Morgan Kaufmann, San Francisco 1995 ISBN1-558-60246-1

• Treatments by one or few authors, often aimed at a more general audience:• Jakob Nielsen: Usability Engineering. Academic Press, Boston 1993 ISBN 0-12-518405-0• Donald A. Norman: The Psychology of Everyday Things. Basic Books, New York 1988 ISBN 0-465-06709-3• Jef Raskin: The humane interface. New directions for designing interactive systems. Addison-Wesley, Boston

2000 ISBN 0-201-37937-6• Ben Shneiderman and Catherine Plaisant: Designing the User Interface: Strategies for Effective

Human–Computer Interaction. 4th ed. Addison Wesley, 2004 ISBN 0-321-19786-0• Bruce Tognazzini: Tog on Interface. Addison-Wesley, Reading 1991 ISBN 0-201-60842-1

• Textbooks that could be used in a classroom:• Alan Dix, Janet Finlay, Gregory Abowd, and Russell Beale (2003): Human–Computer Interaction. 3rd

Edition. Prentice Hall, 2003. http:/ / hcibook. com/ e3/ ISBN 0-13046-109-1• Helen Sharp, Yvonne Rogers & Jenny Preece: Interaction Design: Beyond Human–Computer Interaction, 2nd

ed. John Wiley & Sons Ltd., 2007 ISBN 0-470-01866-6

Human–computer interaction 43

• Matt Jones (interaction designer) and Gary Marsden (2006). Mobile Interaction Design, John Wiley and SonsLtd.

• See also List of user interface literature• See also readings on hcibib.org [36]

External links• Bad Human Factors Designs [37]

• The HCI Bibliography [38] Over 58,000 publications about HCI.• Human-Centered Computing Education Digital Library [39]

• Usability Views [40]

• HCI Webliography [41] with a list of about 100 HCI Organizations worldwide

References[1] ACM SIGCHI Curricula for Human-Computer Interaction (http:/ / old. sigchi. org/ cdg/ cdg2. html#2_1)[2] http:/ / www. ergoweb. com/ news/ detail. cfm?id=352[3] More discussion of the differences between these terms can be found in the ACM SIGCHI Curricula for Human-Computer Interaction (http:/

/ sigchi. org/ cdg/ cdg2. html)[4] Green, Paul (2008). Iterative Design. Lecture presented in Industrial and Operations Engineering 436 (Human Factors in Computer Systems,

University of Michigan, Ann Arbor, MI, February 4, 2008.[5] Pattern Language (http:/ / www. mit. edu/ ~jtidwell/ common_ground_onefile. html)[6] Wickens, Christopher D., John D. Lee, Yili Liu, and Sallie E. Gordon Becker. An Introduction to Human Factors Engineering. Second ed.

Upper Saddle River, NJ: Pearson Prentice Hall, 2004. 185–193.[7] Brown, C. Marlin. Human-Computer Interface Design Guidelines. Intellect Books, 1998. 2–3.[8] http:/ / www. acm. org/ sigchi/[9] http:/ / www. confsearch. org/ confsearch/ faces/ pages/ topic. jsp?topic=hci& sortMode=1& graphicView=true[10] http:/ / www. sigaccess. org/[11] http:/ / www. cscw2011. org/[12] http:/ / www. dis2010. org/[13] http:/ / www. ecscw. org/[14] http:/ / www. acm. org/ conferences/ group/ conferences/ group10/[15] http:/ / hri2010. org/[16] http:/ / www. acm. org/ icmi/ 2010/[17] http:/ / www. its2010. org/[18] http:/ / www. iuiconf. org/[19] http:/ / www. nime. org/[20] http:/ / ubicomp. org/[21] http:/ / www. acm. org/ uist/[22] http:/ / www. interact2009. org/[23] http:/ / hci. uniroma1. it/ avi2008/[24] http:/ / www. mexihc. org/ 2010/ index-eng. html[25] http:/ / www. hci-international. org/[26] http:/ / www. iaria. org/ conferences2010/ ACHI10. html[27] http:/ / www. bcs-hci. org. uk/ hci2008/[28] http:/ / www. ozchi. org/[29] http:/ / www. afihm. org[30] http:/ / www. graphicsinterface. org/[31] http:/ / www. nordichi. org/[32] http:/ / www. interaction-design. org/ encyclopedia/ human_computer_interaction_hci. html[33] http:/ / www. informaworld. com/ bit[34] http:/ / hci-journal. com/[35] http:/ / www. tandf. co. uk/ journals/ titles/ 07370024. asp[36] http:/ / www. hcibib. org/ readings. html[37] http:/ / www. baddesigns. com[38] http:/ / www. hcibib. org/[39] http:/ / hcc. cc. gatech. edu/

Human–computer interaction 44

[40] http:/ / www. usabilityviews. com/[41] http:/ / www. hcibib. org/ hci-sites/ ORGANIZATIONS. html

Repetitive strain injury

Repetitive Strain InjuryClassification and external resources

DiseasesDB 11373 [1]

eMedicine pmr/97 [2]

MeSH D012090 [3]

Repetitive strain injury (RSI) (also known as repetitive stress injury, repetitive motion injuries, repetitivemotion disorder (RMD), cumulative trauma disorder (CT), occupational overuse syndrome, overusesyndrome, regional musculoskeletal disorder) is an injury of the musculoskeletal and nervous systems that may becaused by repetitive tasks, forceful exertions, vibrations, mechanical compression (pressing against hard surfaces), orsustained or awkward positions.[4]

Types of RSIs that affect computer users may include non-specific arm pain[5] or work related upper limbdisorder (WRULD). Conditions such as RSI tend to be associated with both physical and psychosocial stressors.[6]

Illness

SymptomsThe following complaints are typical in patients who might receive a diagnosis of RSI:[7]

• Pain in the arm, back, shoulders, wrists, or hands (typically diffuse – i.e. spread over many areas).• The pain is worse with activity.• Weakness, lack of endurance.In contrast to carpal tunnel syndrome, the symptoms tend to be diffuse and non-anatomical, crossing the distributionof nerves, tendons, etc. They tend not to be characteristic of any discrete pathological conditions.

FrequencyA 2008 study showed that 68% of UK workers suffered from some sort of RSI, with the most common problemareas being the back, shoulders, wrists, and hands.[8]

Physical examination and diagnostic testingThe physical examination discloses only tenderness and diminished performance on effort-based tests such as gripand pinch strength—no other objective abnormalities are present. Diagnostic tests (radiological,electrophysiological, etc.) are normal. In short, RSI is best understood as an apparently healthy arm that hurts.Whether there is currently undetectable damage remains to be established.

Repetitive strain injury 45

DefinitionThe term "repetitive strain injury" is most commonly used to refer to patients in whom there is no discrete, objective,pathophysiology that corresponds with the pain complaints. It may also be used as an umbrella term incorporatingother discrete diagnoses that have (intuitively but often without proof) been associated with activity-related arm painsuch as carpal tunnel syndrome, cubital tunnel syndrome, thoracic outlet syndrome, DeQuervain's syndrome,stenosing tenosynovitis/trigger finger/thumb, intersection syndrome, Golfer's elbow (medial epicondylosis), Tenniselbow (lateral epicondylosis), and focal dystonia.Finally RSI is also used as an alternative or an umbrella term for other non-specific illnesses or general terms definedin part by unverifiable pathology such as reflex sympathetic dystrophy syndrome (RSDS), Blackberry thumb,disputed thoracic outlet syndrome, radial tunnel syndrome, "gamer's thumb" (a slight swelling of the thumb causedby excessive use of a gamepad), "Rubik's wrist" or "cuber's thumb" (tendinitis, carpal tunnel syndrome, or otherailments associated with repetitive use of a Rubik's Cube for speedcubing), "stylus finger" (swelling of the handcaused by repetitive use of mobile devices and mobile device testing.), "Raver's wrist", caused by repeated rotationof the hands for many hours (for example while holding glow sticks during a rave).Although tendinitis and tenosynovitis are discrete pathophysiological processes, one must be careful because theyare also terms that doctors often use to refer to non-specific or medically unexplained pain, which they theorize maybe caused by the aforementioned processes.

Repetitive strain injury 46

TreatmentThe best sort of treatment you can get for having RSI is frequent rests and exercise.

ErgonomicsModifications of posture and arm use (ergonomics) are often recommended.[9]

Ergonomics: the science of designing the job, equipment, andworkplace

Adaptive software

There are several kinds of software designed to help inRepetitive Strain Injury. Among them, there are speechrecognition software, and break timers. Break timerssoftware reminds the user to pause frequently andperform exercises while working behind a computer.There is also automated mouse-clicking software that hasbeen developed, which can automate repetitive tasks ingames and applications.

Adaptive hardware

Adaptive technology ranging from special keyboards,mouse replacements to pen tablet interfaces might helpimprove comfort.

Mouse

Switching to a much more ergonomic mouse, such as aroller mouse, vertical mouse or joystick, or switchingfrom using a mouse to using a stylus pen with graphictablet may provide relief, but in chronic RSI they mayonly result in moving the problem to a different area.Using a graphic tablet for general pointing, clicking, anddragging (i.e. not drawing) may take some time to getused to as well. Switching to a trackpad, which requiresno gripping or tensing of the muscles in the arms may help as well. Inertial mouses (which do not require a surface tooperate) might offer an alternative where the user's arm is in a less stressful thumbs up position rather than rotated tothumb inward when holding a normal mouse. Also, since they do not need a surface to operate ("air mouses"function by small, forceless, wrist rotations), the wrist and arm can be supported by the desktop.

Repetitive strain injury 47

Keyboards and keyboard-alternatives

Exotic keyboards by manufacturers such as Datahand, OrbiTouch, Maltron and Kinesis are available.

DataHand Professional II Keyboard,right side

Medical

A number of medical treatments, including non-narcotic pain medications,braces, and therapy, exist although some doctors consider these to bepalliative.[10] [11] (See Are Some RSI Cases Psychosomatic? below)

Exercise

Exercise decreases the risk of developing RSI.[12]

• Doctors sometimes recommend that RSI sufferers engage in specificstrengthening exercises, for example to improve posture.

• In light of the fact that a lifestyle that involves sitting at a computer forextended periods of time increases the probability that an individual willdevelop excessive kyphosis, theoretically the same exercises that areprescribed for thoracic outlet syndrome or kyphotic postural correctionwould benefit an RSI sufferer.[13]

Resume Normal Activities Despite the Pain?Some researchers believe that, for the most difficult chronic RSI cases, the pain itself becomes less of a problem thanthe disruption to the patient's life caused by• avoidance of pain-causing activities• massive investment of time into increasingly futile attempts at treatmentThey claim greater success from teaching patients psychological strategies for accepting the pain as an ongoing factof life, enabling them to cautiously resume many day-to-day activities and focus on aspects of life other than RSI.[14]

Others disagree, emphasizing the importance of rest in achieving recovery. For instance, it has been claimed thatrecovery can take up to 8 months without performing activities that might exacerbate the symptoms, and that theaffected joint should never be put under severe or constant stress.

Psychosocial factors

Population studiesStudies have related RSI and other upper extremity complaints with psychological and social factors. A large amountof psychological distress showed doubled risk of the reported pain, while job demands, poor support fromcolleagues, and work dissatisfaction also showed an increase in pain, even after short term exposure.[15]

For example, the association of Carpal tunnel syndrome with arm use is commonly assumed but notwell-established.[16] Typing has long been thought to be the cause of carpal tunnel syndrome,[17] but recent evidencesuggests that, if anything, typing may be protective.[18] Another study claimed that the primary risk factors forCarpal tunnel syndrome were "being a woman of menopausal age, obesity or lack of fitness, diabetes or having afamily history of diabetes, osteoarthritis of the carpometacarpal joint of the thumb, smoking, and lifetime alcoholintake."[19]

Repetitive strain injury 48

Psychological exacerbation of symptomsThere are three common mechanisms, by which a normally functioning human mind increases pain and pain-relateddisability.• Psychological distress (depression and anxiety) make pain seem worse.[20] Chronic pain, regardless of its source,

leads to a cycle of increasing depression and reduced physical activity. Reduced physical activity reduces pain inthe short term but increases it in the long term.[21]

• Misinterpretation or over-interpretation of pain signals. Psychologists refer to this as pain catastrophizing (thetendency to think the worst when one feels pain),[7] and it is worsened by reliance on patient support groups andinternet sites for diagnosis.[22] Gate Control Theory, part of the most accepted medical theory of pain, states that,when we are worried about a particular body part, the brain can actually signal to the spinal cord (via outgoingneurons) that it should be more apt to interpret nerve impulses from that body part as pain and pass them on to thebrain.[23] . In patients with chronic arm pain, the brain may even learn to automatically trigger pain whenever thelimb is moved, as a defense mechanism to prevent further movement[24]

• A sense that something is seriously wrong that does not lessen with normal test results and reassurance fromhealth professionals.[25] Psychologists call this heightened illness concern or health anxiety. (This is commonlyseen in psychosomatic illnesses.[26] .) The typical RSI patient presents with a strong intuition that their painindicates existing and ongoing tissue damage.[25] One explanation is that they have a strong "pain alarm"—paintends to be accepted as a sign of danger and they have difficulty modulating this intuitive uneasiness with pain.[7]

.

Psychosomatic casesSome doctors and medical researchers believe that stress is the main cause, rather than a contributing factor, of alarge fraction of pain symptoms usually attributed to RSI. The most famous advocate of this point of view, Dr. JohnE. Sarno, Professor of Rehabilitation Medicine at the New York University Medical School considers that RSI, backpain, and other pain syndromes, although they sometimes have a physical cause, are more often a manifestation oftension myositis syndrome, a psychogenic disorder in which stress causes the autonomic nervous system to reduceblood flow to muscles, causing pain and weakness.[27]

RSI shares many characteristics with known psychosomatic disorders:• Freud and other psychiatrists believe that diffuse, difficult to describe symptoms likely indicated a psychosomatic

root cause for an illness, especially if they moved around the body.[26] (Only some RSI cases fit this description.)• Psychosomatic illnesses typically display symptoms whose origins are unverifiable but which seem consistent

with the time period's understanding of physical (non-psychosomatic) disease processes. When an objective testinvented which is able to prove the psychosomatic origins of a specific illness, that illness typically disappearsand is replaced by new, undiagnosable sets of symptoms.[26]

• Patients and their advocates usually reject the suggestion that their disease may be non-physical in origin. Doctorsfrequently avoid giving psychosomatic diagnosis, for fear of angering patients or prompting them to switchdoctors.[26] . "Psychosomatic" is often misunderstood to mean "faking it" or "imaginary". [26] Otherpsychosomatic diseases have been known to cause severe pain, paralysis, seizures[26] , observable physicaldamage, even death.[28] .

A common theme among different subtypes of RSI is a stigmatization and demonization of hand use. Illness concepts that stigmatize hand use have the potential to create more illness as well-documented in the experience with the Australian RSI epidemic. [10] RSI was first diagnosed in Australia in the 1980s. (Only later was it diagnosed in the US and Britain.) In the early Australian experience, RSI cases increased rapidly over several years, leading to widespread media coverage and worker protests. After a widely publicized court case in which a judge ruled an alleged RSI victim had no bodily injury and could not receive damages, complaints dropped off rapidly. Many observers felt that the media coverage and social mobilization against the epidemic had actually helped spread it by

Repetitive strain injury 49

causing psychosomatic symptoms in worried workers.[29] This pattern has been seen in other psychosomaticillnesses.[26]

See also• List of Repetitive Strain Injury software• Carpal tunnel syndrome

ReferencesReferences that support or promote use of the physical illness concept of RSI• Repetitive Strain Injury: A Computer User's Guide; Emil Pascarelli and Deborah Quilter (ISBN 0-471-59533-0)• It's Not Carpal Tunnel Syndrome! RSI Theory and Therapy for Computer Professionals; Suparna Damany, Jack

Bellis (ISBN 0-9655109-9-9)• Conquering Carpal Tunnel Syndrome & Other Repetitive Strain Injuries, A Self-Care Program; Sharon J. Butler

(ISBN 1-57224-039-3)• The Trigger Point Therapy Workbook: Your Self-Treatment Guide for Pain Relief, Second Edition; Clair Davies,

Amber Davies (ISBN 1-57224-375-9)• Electromyographic Applications in Pain, Physical Medicine and Rehabilitation: Repetitive Strain Injury

Computer User Injury With Biofeedback: Assessment and Training Protocol; Erik Peper, Vietta S Wilson et al.The Biofeedback Foundation of Europe, 1997

• van Tulder M, Malmivaara A, Koes B (2007). "Repetitive strain injury". Lancet 369 (9575): 1815–22.doi:10.1016/S0140-6736(07)60820-4. PMID 17531890.

References that are cautious about the use of the physical illness concept of RSI• Szabo RM, King KJ (September 2000). "Repetitive stress injury: diagnosis or self-fulfilling prophecy?" [30]. J

Bone Joint Surg Am 82 (9): 1314–22. PMID 11005523. Review.• Ring D, Guss D, Malhotra L, Jupiter JB (July 2004). "Idiopathic arm pain" [31]. J Bone Joint Surg Am 86-A (7):

1387–91. PMID 15252084.• Quintner JL (July 1995). "The Australian RSI debate: stereotyping and medicine". Disabil Rehabil 17 (5):

256–62. doi:10.3109/09638289509166644. PMID 7626774.• Hall W, Morrow L (1988). "'Repetition strain injury': an Australian epidemic of upper limb pain". Soc Sci Med 27

(6): 645–9. doi:10.1016/0277-9536(88)90013-5. PMID 3227370.• Lucire Y. Constructing RSI: Belief and Desire. University of New South Wales Press. 2001• Brooks P (November 1993). "Repetitive strain injury" [32]. BMJ 307 (6915): 1298.

doi:10.1136/bmj.307.6915.1298. PMID 8257882. PMC 1679411.

External links• Repetitive Strain Injuries [33] at the Open Directory Project• Musculoskeletal disorders [34] from the European Agency for Safety and Health at Work (EU-OSHA)• Workrave [35] application for prevention of RSI• Amadio PC (January 2001). "Repetitive stress injury" [36]. J Bone Joint Surg Am 83-A (1): 136–7; author reply

138–41. PMID 11205849.• Harvard RSI Action [37]

• Prevention and Management of Repetitive Strain Injury [38]

• My work, my sorrow, a documentary on RSI in France today

Repetitive strain injury 50

References[1] http:/ / www. diseasesdatabase. com/ ddb11373. htm[2] http:/ / www. emedicine. com/ pmr/ topic97. htm[3] http:/ / www. nlm. nih. gov/ cgi/ mesh/ 2010/ MB_cgi?field=uid& term=D012090[4] http:/ / www. state. nj. us/ health/ eoh/ peoshweb/ ctdib. htm[5] Teixeira, Tania (2008-12-09). "Technology | The mouse is biting some PC users" (http:/ / news. bbc. co. uk/ 1/ hi/ technology/ 7761262. stm).

BBC News. . Retrieved 2009-08-17.[6] Macfarlane, Hunt, Silman. Role of mechanical and psychosocial factors in the onset of forearm pain: prospective population based study.

BMJ. 2000[7] Ring D, Kadzielski J, Malhotra L, Lee SG, Jupiter JB (February 2005). "Psychological factors associated with idiopathic arm pain" (http:/ /

www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=15687162). J Bone Joint Surg Am 87 (2): 374–80. doi:10.2106/JBJS.D.01907.PMID 15687162. .

[8] "Two thirds of office staff suffer from repetitive strain injury | Mail Online" (http:/ / www. dailymail. co. uk/ health/ article-1024097/Two-thirds-office-staff-suffer-Repetitive-Strain-Injury. html). Dailymail.co.uk. 2008-06-04. . Retrieved 2009-08-17.

[9] Berkeley Lab. Integrated Safety Management: Ergonomics (http:/ / www. lbl. gov/ ehs/ pub811/ hazards/ ergonomics. html). Website.Retrieved 9 July 2008.

[10] Amadio PC (January 2001). "Repetitive stress injury" (http:/ / www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=11205849). J BoneJoint Surg Am 83-A (1): 136–7; author reply 138–41. PMID 11205849. .

[11] Living Beyond Your Pain: Using Acceptance & Commitment Therapy to Ease Chronic Pain by Joanne Dahl and Tobias Lundgren[12] Ratzlaff, C. R.; J. H. Gillies, M. W. Koehoorn (April 2007). "Work-Related Repetitive Strain Injury and Leisure-Time Physical Activity".

Arthritis & Rheumatism (Arthritis Care & Research) 57 (3): 495–500. doi:10.1002/art.22610. PMID 17394178.[13] Carolyn Kisner & Lyn Allen Colby, Therapeutic Exercise: Foundations and Techniques, at 473 (5th Ed. 2007).[14] Living Beyond Your Pain: Using Acceptance & Commitment Therapy to Ease Chronic Pain by Joanne Dahl and Tobias Lundgren[15] Nahit ES, Pritchard CM, Cherry NM, Silman AJ, Macfarlane GJ (June 2001). "The influence of work related psychosocial factors and

psychological distress on regional musculoskeletal pain: a study of newly employed workers" (http:/ / www. jrheum. org/ cgi/pmidlookup?view=long& pmid=11409134). J. Rheumatol. 28 (6): 1378–84. PMID 11409134. .

[16] Lozano-Calderón S, Anthony S, Ring D (April 2008). "The quality and strength of evidence for etiology: example of carpal tunnelsyndrome" (http:/ / linkinghub. elsevier. com/ retrieve/ pii/ S0363-5023(08)00008-7). J Hand Surg Am 33 (4): 525–38.doi:10.1016/j.jhsa.2008.01.004. PMID 18406957. .

[17] Scangas G, Lozano-Calderón S, Ring D (September 2008). "Disparity between popular (Internet) and scientific illness concepts of carpaltunnel syndrome causation" (http:/ / linkinghub. elsevier. com/ retrieve/ pii/ S0363-5023(08)00281-5). J Hand Surg Am 33 (7): 1076–80.doi:10.1016/j.jhsa.2008.03.001. PMID 18762100. .

[18] Atroshi I, Gummesson C, Ornstein E, Johnsson R, Ranstam J (November 2007). "Carpal tunnel syndrome and keyboard use at work: apopulation-based study" (http:/ / www3. interscience. wiley. com/ journal/ 116835897/ abstract). Arthritis Rheum. 56 (11): 3620–5.doi:10.1002/art.2295610.1002/art.22956. PMID 17968917. .

[19] Falkiner S, Myers S (March 2002). "When exactly can carpal tunnel syndrome be considered work-related?" (http:/ / www3. interscience.wiley. com/ resolve/ openurl?genre=article& sid=nlm:pubmed& issn=1445-1433& date=2002& volume=72& issue=3& spage=204). ANZ JSurg 72 (3): 204–9. doi:10.1046/j.1445-2197.2002.02347.x. PMID 12071453. .

[20] Ring D, Kadzielski J, Fabian L, Zurakowski D, Malhotra LR, Jupiter JB (September 2006). "Self-reported upper extremity health statuscorrelates with depression" (http:/ / www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=16951115). J Bone Joint Surg Am 88 (9): 1983–8.doi:10.2106/JBJS.E.00932. PMID 16951115. .

[21] Turk and Winter. The Pain Survival Guide: How to Reclaim Your Life[22] Taylor, Steven J.; Asmundson, Gordon J. G. (2005). It's Not All in Your Head: How Worrying about Your Health Could be Making You

Sick—and What You Can Do about It. New York: The Guilford Press. ISBN 1-57230-993-8.[23] Brannon and Feist. Health Psychology: An Introduction to Behavior and Health[24] page 193. The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science.[25] Vranceanu AM, Safren S, Zhao M, Cowan J, Ring D (November 2008). "Disability and psychologic distress in patients with nonspecific and

specific arm pain" (http:/ / www. pubmedcentral. nih. gov/ articlerender. fcgi?tool=pmcentrez& artid=2565030). Clin. Orthop. Relat. Res. 466(11): 2820–6. doi:10.1007/s11999-008-0378-110.1007/s11999-008-0378-1. PMID 18636306. PMC 2565030.

[26] Shorter, Edward (1992). From Paralysis to Fatigue: A History of Psychosomatic Illness in the Modern Era. New York: Free Press ; Toronto: Maxwell Macmillan Canada ; New York : Maxwell Macmillan International. ISBN 0-02-928665-4.

[27] Sarno, John E (2006). The Divided Mind: The Epidemic of Mindbody Disorders. Regan Books. ISBN 978-0060851781.[28] The science of voodoo: When mind attacks body. New Scientist. 2009[29] Lucire, Yolande (2003). Constructing RSI: Belief and Desire. Sydney: University of New South Wales Press. ISBN 0-86840-778-X.[30] http:/ / www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=11005523[31] http:/ / www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=15252084[32] http:/ / www. pubmedcentral. nih. gov/ articlerender. fcgi?tool=pmcentrez& artid=1679411[33] http:/ / www. dmoz. org/ Health/ Conditions_and_Diseases/ Musculoskeletal_Disorders/ Repetitive_Strain_Injuries/ /

Repetitive strain injury 51

[34] http:/ / osha. europa. eu/ topics/ msds[35] http:/ / www. workrave. org/[36] http:/ / www. ejbjs. org/ cgi/ pmidlookup?view=long& pmid=11205849[37] http:/ / www. rsi. deas. harvard. edu/[38] http:/ / www. eecs. umich. edu/ ~cscott/ rsi. html

Article Sources and Contributors 52

Article Sources and ContributorsHuman factors  Source: http://en.wikipedia.org/w/index.php?oldid=370912365  Contributors: Adam M. Gadomski, Adyar, Aelyan, Alainr345, Alfpooh, Altenmann, Ammalu, Arthurrohan,Benlisquare, BillFlis, Black Pullet, Ciphers, Cnj, Cswrye, DCDuring, DavidLevinson, Dkoya, DoctorW, Dominus, Dreamyshade, Dysprosia, Eagle1711, Eastlaw, Edward, Eptin, Ergolight,Eshaver, Frecklefoot, Fuhghettaboutit, Gary King, Gene Hobbs, Gepwiki, Gulshan12, HFiCS, Harald.schaub, Heimstern, Hugh McLoone, Jamelan, Jaroslavleff, Jj137, Jlstemp, Jomackiewicz,JteB, Just plain Bill, Jwphara, KJie.Neo, KMcGrane, KnockItOff, Kroede, Letranova, Levine2112, Mahanga, Martinevans123, Masoudsa, Mdd, Mel Etitis, Michshin387, Minglex, Motherh,Mtjs0, Myleslong, Nakon, NielsenGW, Nightscream, Nroubal, Oicumayberight, Oo64eva, Optakeover, PatGallacher, Paulmallon, Pavel Vozenilek, Peter Budnick, PetterEkhem, Pmjones,Pnikneja, Pzavon, RJBurkhart, Rani Lueder, Rdmoore, Rikipedia8, Rjwilmsi, Robinsuz, Ronz, RoodyAlien, Royalbroil, SaRSUK, Sandrouille, Saric, SeanGustafson, Sidna, Spalding, Spawnkie,StefanoC, Stephenb, Suilline, Swpb, Teratornis, Themoonisgreen, Thisisbossi, Thorkil9, Tiddly Tom, Tkalley, Tntdj, Tscud, Umeshghosh, Von Mario, Wfu, WhatamIdoing, Winslow Peck,Yamamoto Ichiro, Zian, 174 anonymous edits

Ergonomics  Source: http://en.wikipedia.org/w/index.php?oldid=370625267  Contributors: (jarbarf), -Midorihana-, 13Anonymous 49, 208.160.249.xxx, 5 albert square, ABF, AThing,Aaroncrick, Abune, Acalamari, Acroterion, Addshore, AdjustShift, Aff123a, Aishel, Aitias, AlainV, Alan Isherwood, Alansohn, Alexius08, Alksentrs, Altenmann, Andre Engels, Andyjsmith,Anetode, AngelOfRetribution, Anger22, Anonymous Dissident, Apeloverage, Apparition11, Arctic Fox, Arjun G. Menon, Armaneimanseema, Arpingstone, Arvindn, Baldhur, Bart133,Beckysmarshall, Benlisquare, Bhargavi Raman, Big Bird, Billpapa, Bjaradat, Blademontane, BloodDoll, Bob Hu, Bobak, Bobblewik, Bobo192, Bodachi, Bonaparte, Bookandcoffee, Bowb,Brageira, Brat32, BrokenSphere, Brougham96, Buchanan-Hermit, Bullzeye, Butros, Caltas, Calvin 1998, Can't sleep, clown will eat me, CanadianLinuxUser, Capricorn42, Captain-tucker,CardinalDan, Cassandra 73, Chaojoker, Chasingsol, Chris G, Chrisch, Chzz, Ckatz, Closedmouth, Cobi, Connah0047, Conversion script, Correogsk, Corti, Courcelles, Cquan, Cstormer, Cswrye,Cxz111, DBOLTSON, DCDuring, Da monster under your bed, DanielCD, Danthemankhan, Dark 1 one, Dattebayo321, Davington123, Dawidbernard, Dcsohl, DeadEyeArrow, Dekisugi, Deli nk,Delirium, Delldot, Derek Ross, Desertsky85451, Dickpenn, Diego Moya, Discospinster, Dlohcierekim, Dominic Hardstaff, Duncan, E-pen, EJF, ESkog, Earthsound, Edgar181, Edhubbard,Editor2020, Efuerst, El C, Elassint, Eleassar, Emmett5, Enviroboy, Equendil, Excirial, EyeSerene, Fantasy, Fatal!ty, Favonian, Feezo, Feinoha, Felyza, Fgrose, Flamurai, Flclhack, Flipper3441,FlyHigh, Frap, Freakofnurture, Fredwerner, Fritzpoll, Funandtrvl, Gary King, Gator1, GeneralCheese, George The Dragon, Gfkajgfdljfkdajfsjklafjdf, Gilliam, Gogo Dodo, GraemeL, Grafixical,Graham87, Grimey109, Grubber, Gurch, Gwguffey, Hadal, Hagarthehorrible, Hammer1980, Hannahm23, Hanwufu, Harrybyles1996, Hburg, Hdt83, HenkvD, Hertz1888, HiLo48, Holden 94,Honta, Hu12, Hugh McLoone, Hut 8.5, I myk I, Iaculch, Ian13, Ibv-com, IcedNut, Icseaturtles, Ignatzmice, Immunize, IndulgentReader, Intgr, Iridescent, Isfisk, Iss246, J.delanoy, JDiPierro,JJGD, Jackol, Jake Wartenberg, Jamesooders, Japo, Jason7825, Jeh, Jennavecia, Jewong, Jfdwolff, Jizish, Jjjsixsix, Jmundo, Jni, JohnCD, Jojojo22, JubalHarshaw, Juliancolton, Jusdafax, Jusjih,Just plain Bill, Jw4774, KPbIC, Kakofonous, Karesz1h, Katalaveno, Kaustuv, Kbdank71, KezianAvenger, Kgasso, Kingpin13, KnowledgeOfSelf, Koolpeep429, Kosebamse, KoshVorlon,KrakatoaKatie, Kralizec!, Krich, Kubigula, Kuru, Kurykh, Kusyadi, Kwsn, Lacort, Ladypine, Laurel 310, Leafyplant, LeaveSleaves, Leujohn, Levine2112, Ligulem, Linnell, LittleOldMe,Lockley, Lol1001, Loren.wilton, Lwalt, M.nelson, MC10, MER-C, MIT Trekkie, MONGO, MacMed, MadK3, Maestroso simplo, Magda., Magog the Ogre, Malcolmxl5, Mandarax, Mandretta,MangoCopter, Marek69, Mark Renier, MarkGallagher, Martial75, Martin451, Martinevans123, Masoudsa, Mathwhiz 29, Matt9363, Matticus78, Maxim, Mbc362, McSly, Mcarmody, Mdd,Mdobbie, Meavel, Mentifisto, MichaelMaggs, Midgrid, Mifter, Minnaert, Moreschi, Moritz, Mptsk, Mtjs0, MuDavid, Muenda, Muiranec, Multi-wall, Muntfish, NMChico24, Nagy, Natalie Erin,NauarchLysander, NawlinWiki, Ncmvocalist, NeoJustin, NewEnglandYankee, NiggardlyNorm, Nishkid64, Nkour, Nroels, Nsaa, NuclearWarfare, Nucleusboy, Oda Mari, Odie5533,Ohnoitsjamie, Olivier, Oloumi, OnBeyondZebrax, Onodevo, Onorem, Orangeblender, Otolemur crassicaudatus, Ourai, Oxymoron83, Paolor, Papergirl22, Paranomia, Patman, Paul August, PavelVozenilek, PeaceNT, Pearle, Pedro, Peter Budnick, Peterlewis, Pharaoh of the Wizards, Phatom87, Phe, Phil Bridger, Phila 033, Philip Trueman, Philippe, Piano non troppo, Pingveno,Plokminhdfkv, Pmjones, Pnk8bubble2, PolarBear506, Posturite, Ppntori, Precisedjs, Prof saxx, Protonk, Puchiko, Pzavon, Qaddosh, Qst, Quadell, Quadrius, Quaeler, Qwertyuioper2, R'n'B,R0pe-196, RSM, Racepacket, Radagast83, RainbowOfLight, Rajkur, Randkgo, Rani Lueder, RaseaC, Raywil, Reach Out to the Truth, RedHouse18, Regibox, Reindra, Remohammadi,Res2216firestar, Retired username, Rettetast, Revth, RexNL, Rhys1994, Rich Farmbrough, Rknasc, Robinh, Ronz, Rrburke, Rtcpenguin, Rubicon Line, S, SHoCKu386, Sam Blacketer, SampiEuropa, Samw, Sannse, Schmancy47, Sciurinæ, Shalom Yechiel, ShelleyAdams, Sholto Maud, Shreshth91, Sigmundg, Simeon24601, Sitethief, Sk8er5000, Skyezx, Slakr, Slipstream, SoarAero,Spalding, Squids and Chips, Ssbb4, Stefonalfaro, Stephenb, Subverted, SueHay, SunCreator, Sunny256, Synchronism, Tagishsimon, Tarquin, Technopat, Tetraedycal, Thatguyflint, Thatperson,The Anome, The Thing That Should Not Be, The Wild Falcon, The cattr, Theo F, Theoneintraining, ThinkBlue, Thirteen squared, Tholly, Thunderboltz, Tide rolls, Tisdalepardi, Tlevine,Tomandgavin, Traxs7, Trevor MacInnis, Trr, Tyr967, Ukexpat, Umeshghosh, Umidrb, Uncle Dick, Unisex, Unschool, UserPerson, Utcursch, Vary, VasilievVV, Veinor, Versus22,Videodude1298, Vindi293, Vipinhari, Vpdvpd, WLU, Wavelength, Wayne Riddock, WikHead, Wiki Raja, Wimt, Wkarwowski, Wolfkeeper, Woohookitty, Worksafe, Xezbeth, XxTimberlakexx,Yaniss, Zaidiutm, Zmilot, Zooweee, Zudduz, 1581 anonymous edits

Anthropometry  Source: http://en.wikipedia.org/w/index.php?oldid=368385005  Contributors: -m-i-k-e-y-, 04kingj, 16@r, AVM, Abdull, AlecChristensen, Amcaja, Angela, Apers0n, BackslashForwardslash, Bfurlong, Bobo192, Brionthorpe, Brusegadi, Ceyockey, Chamal N, Charles Merriam, CharlesC, Chase me ladies, I'm the Cavalry, Cire27, Closedmouth, Comerb15, Countskull,Cruise, DCDuring, DVD R W, Dcoetzee, Dekisugi, DerAnstifter, Detruncate, Dogposter, EagleFan, Edward321, Eliz81, Elrodriguez, Emvee, Epbr123, Eras-mus, Eric119, Fastfission, Favonian,FayssalF, Fubar Obfusco, Gcm, Gene Nygaard, George.h.01, Gina Nicole, Glogger, Glueball, GregorB, Grow60, Habj, Icydid, Imark 02, Invasion10, IronGargoyle, J-V Heiskanen, Jason Potter,Jfdwolff, Jj137, Jni, JoeCotellese, Joeklein, Joseph Solis in Australia, Joy, Jtimleck, JzoJames, KT322, Kafziel, Kateshortforbob, Keesiewonder, Kenyon, Kusyadi, L beaumanior, Lapaz, Leonski,M arpalmane, Markus Kuhn, Mccajor, Melaen, Michael Devore, Michael Hardy, Middenface, N0YKG, Necrothesp, NickelShoe, Nigelkr, Palapa, Pete.Hurd, Phony Saint, Physchim62,Pizza1512, Pwqn, Rani Lueder, Rayray, Reedy, Reskin, Richardallen42, RxS, SCooley138, Salsb, Samw, Sandstein, Shao, Shizhao, SimonP, Skarebo, Tazmaniacs, The Thing That Should NotBe, Thorkil9, Tobias Bergemann, Triwbe, Usien6, Vancevlasak, Verne Equinox, West.andrew.g, Woohookitty, 159 ,ملاع بوبحم anonymous edits

Rohmert's law  Source: http://en.wikipedia.org/w/index.php?oldid=344133053  Contributors: CanisRufus, Edgar181, JIP, Michael Hardy, No Guru, Oracleofottawa, RHaworth, Stemonitis, Thewub, Thiseye, 6 anonymous edits

Experience design  Source: http://en.wikipedia.org/w/index.php?oldid=366526918  Contributors: Ajcheng, Alainr345, Apophenia, Barkeep, Beland, Bob Jacobson, Brazandre, Bristolian46,Claude Bla, Cyberoid, Ehheh, Gyokomura, Hu12, I.A.Contino, Joepemberton, Kungfuadam, Lauriehaycock, Len Raymond, Letranova, MKawasaki, Marcovanhout, Michael Hardy,Oicumayberight, Owlmonkey, Pvodenski, Requestion, Rjb154, Ronz, Salvagione, UnkleFester, Vanderbeeken, WildfireSOMA, 40 anonymous edits

Industrial design  Source: http://en.wikipedia.org/w/index.php?oldid=372294061  Contributors: A5y, Aaronbrick, Aboutmovies, Adriancbennett, Ahoerstemeier, Alainr345, Alex756, Alfpooh,Alftecumseh, Alikaalex, Allan McInnes, Amaritudo, Amaunimiso, Andrewpmk, Andryono, Arichnad, Auntof6, Average Earthman, Avogadro94, Baa, Bbrejcha, BenFrantzDale, Biwiki394,Blue387, BlueMech, Bobo192, Bristolian46, Broogie, Bruce wasserman, Bultro, Burpelson AFB, CUSENZA Mario, Calvin 1998, Can't sleep, clown will eat me, Catgut, Cbdorsett, Cenarium,Chimin 07, Ciphers, Clayoquot, Clubmarx, Combuchan, CoolKoon, Core77no1!, Cybercobra, DAJF, DK.SW, DMCer, DVD R W, David Newton, DavidPedia, Dczoner, Dekisugi, Der Falke,Designcouncil, Designerx, Dezignr, Edcolins, Eddie.willers, Elrond Nólatári, Eptin, Fdepraetere, Femto, Francs2000, Frankpeters, Fred Bauder, GB fan, Gaius Cornelius, Goldenrowley,GraemeL, Gregball, Guswen, Gutt2007, Hadal, Haeleth, Haham hanuka, Harshmellow, Hayabusa future, Hazelsct, HexaChord, Hotlorp, Hsinava, Hu12, II MusLiM HyBRiD II, IW.HG, Indon,Iridescent, Itactics, JNW, Jd.castellanos, JeremyLydellHaugen, Jersey emt, Jimmi Hugh, JoanneB, Joel Russ, John254, Jovianeye, Juanscott, Julesd, Junbernardo, Kimahonda, Kozuch,Lawrenceofrin, Lexowgrant, Linkspamremover, Lisatwo, Lockley, Loupeter, M.nelson, Macrakis, Malo, Manuelt15, Mboverload, Mcdropkicker, Mellery, Memes, Michael Bednarek, MichaelHardy, Michal Nebyla, MidiUser, Mintleaf, Misceltyms, Mitchwade84, Mmfidler, Morven, Moverton, Mozzerati, Mr kit72, MrArt, Mugwumpman, Muéro, Mwanner, Mydogategodshat, NigelCross, Ninaoffen, Od Mishehu, Oicumayberight, OriginalGamer, Oskar9, P. Rollin, Parametric66, Paulsandip, Pavel Vozenilek, Phillydesign, Physicistjedi, Pion, PocklingtonDan, Ppd808,Proctorg76, Prof saxx, Pseudomonas, RAM, RHaworth, RadRafe, Randhirreddy, Randroide, Regine W, Rene 1, Rizoglou, Rlsheehan, Robko71, Ronz, SAUNDERS, Shipikiw, Sintaku, Skelta,Skinc5239, Slkhui, Sloan2, Sobolewski, Spinster, Stephen Burnett, Strangnet, The Thing That Should Not Be, TheNewPhobia, ThijsN, Tikiwont, Titantr, Todd falkowsky, Tomaat, Trusilver, Vanhelsing, Ve2jgs, Verne Equinox, Versus22, Vikingstad, Viridae, Viriditas, Vpdvpd, Waikitchung, Wampum70, Wars, Wavelength, Woohookitty, Xibo14, Zanimum, Zouavman Le Zouave, 409anonymous edits

Design for All (design philosophy)  Source: http://en.wikipedia.org/w/index.php?oldid=369164121  Contributors: ChristopheS, Dodger67, Intgr, Jcravens42, R'n'B, RadekC, Rehareha,Robofish, Sergio1013, Swpb, Technopat, 12 anonymous edits

Human–computer interaction  Source: http://en.wikipedia.org/w/index.php?oldid=372038385  Contributors: -Midorihana-, AK Auto, Aapo Laitinen, Acerone, Adam J. Sporka, Addshore, AlainV, Alan Au, Aleenf1, Alex Kosorukoff, AlexWaelde, Amniarix, Andicat, AndrewHarvey4, AnonGuy, Anshuk, ArielGold, Art LaPella, Bartneck, Beesforan, Bento00, Bnorrie, Bobo192, Bookuser, Brianvijay, Brichard37, Bryan Derksen, Bwabes, Can't sleep, clown will eat me, Casiez, Chairman S., Chris G, Chrisch, Christian lewis big bang, Cmw44, Colin Barrett, Compo, Conversion script, Crocodile Punter, Cryptic, Cst17, Cyde, D3innovation, DMacks, DXBari, Da monster under your bed, DabMachine, Dave2, David@multisell.ae, Delirium, Dennis Brown, DerrickParkhurst, Devantheryv, Donreed, DoorFrame, Dragice, Dullhunk, Eleusis, Enric Naval, Epbr123, Estumator, Eugenem, Excirial, Favonian, Ferdouna, Flavonoid, Flewis, Fnazir, Forlornturtle, Fratrep, Frodet, GTBacchus, Gary King, Garyperlman, Geoffsauer, Gillianrh, Glendac, Gmd588, Gogo Dodo, Gomm, GraemeL, Graham87, Haipa Doragon, Haloedrain, Hede2000, IMSoP, Ian Pitchford, Ibrahimshamsi, Isnow, IvanLanin, J1mb0jay, Janet Davis, Jat32, Joe3600, Joebeone, John, Jomackiewicz, Jon Awbrey, Joy, JteB, Juliamae, KYPark, Karesz1h, Kaysov, Kenny sh, Kozuch, Kungfuadam, Larry_Sanger, Lear's Fool, Lew1056, Liftarn, Loupeter, Lunzueta78, Lupo, MC10, MER-C, Magicmat, Mahalakshmiks, Mahemoff, Mario1337, Matjack, MaxVeers, Melchoir, Mets501, Michael Hardy, Michael J. Mullany, MichaelMcGuffin, Mintguy, Mj8rybin, Moreschi, MrOllie, Mro, NawlinWiki, Newone, Ninly, Normxxx, Nurg, OrgasGirl, Oysterguitarist, Oyvind1979, Ozgurgunes, PL290, Pandaslaughter, Paranomia, Paul August, Pavel Vozenilek, Pchut, Peter Winnberg, Peterdalsgaard, Piet Delport, Psychonaut, Purgatory Fubar, Pzaphiri, Quackor, Raguks, Ramu50, Rapty, RedWolf, Requestion, Riadlem, Rich Farmbrough, Rick.G, Ripepette, Rjwilmsi, RobertG, Ronz, Royboycrashfan, Rror, Ryan Postlethwaite, S.K., SMC, Safincher, Salix alba, Sam Hocevar, SeanGustafson, Seejay220, Shadowlynk, Shalom Yechiel, Shoessss, Showard, SimonP, Soney, Spalding, Stolterman, SupperTina, Suruena, Szlassa, THF, Tamaratrouts, Tauseefzahid, Tdmartinalonso, Teryx, Thcieditor, The Literate Engineer, The Thing That Should Not Be, Thumbarger, Tntdj, Tobias Hoevekamp, Toreau, Tpl, Utcursch,

Article Sources and Contributors 53

Veghead, Veinor, Violetriga, Wani.., Warfvinge, Watcher, Wik, Wikinstone, William Graham, Wonglkd, Woohookitty, Xandi, Yijisoo, Ykhwong, Zeppomedio, Zunaid, Zzyzx11, لیقع فشاک,475 anonymous edits

Repetitive strain injury  Source: http://en.wikipedia.org/w/index.php?oldid=370080118  Contributors: -- April, -Kerplunk-, A.r.dobbs, A3RO, A8UDI, ACMERick, AVRS, Abs0n, Adashiel,Afors, Ahoerstemeier, Alansohn, AlbanScot, AlexChurchill, Alexbr82, Algorithme, Alz, Andrewpmk, Andrewski, Andy M. Wang, Andycjp, Anoko moonlight, Anthonyhcole, Apapadop,Applehead77, Aqwis, Arcadian, Area5x1, Ashmoo, Avnjay, Bellemichelle, Belovedfreak, Bendono, Bidishnay, Bigmissbossy, Blodulv, BobKawanaka, Brw12, Burn, C.Fred, CJTweedy, Caltas,Camster360, Can't sleep, clown will eat me, Cfp, Channelz, Chrislk02, Clairebutterly, CliffC, Cliffb, Colemak fan, Conversion script, Corti, CrazyLegsKC, Croctotheface, DBOLTSON,DarkFalls, Darrenhusted, Darth Panda, Dave3457, Davidruben, Deborah-jl, Delldot, Delpino, Denelson83, Destynova, Dr311, Dutchboy-boston, Earlypsychosis, Eddiesiret, Edgar181, Eequor, ElC, Eloquence, Emmataylor101, Emmerrx, Epbr123, EronMain, Espoo, Euryalus, Falcon8765, Fantasy, Floaterfluss, Floraaaaaa, Fran Rogers, Friginator, Fyyer, Gary King, GateKeeper,Gesinegesine, Giftlite, Gnowor, Gothictitties, Graham87, Greg Kuperberg, GregorB, Gronky, Hairy Dude, Hammer1980, Henry W. Schmitt, HexaChord, Hexacorde, Homo sapiens, Hordaland,Iaen, Imjewish, ImperatorExercitus, InvictaHOG, Irishguy, J Di, JRM, JTSchreiber, Jake Wartenberg, James Frankcom, Jennifer7, Jetpeach, Jfdwolff, Jim Douglas, Jimfbleak, Jmh649, Jnothman,Jogloran, JordoScotto, Joshua200000, Joyous!, Juch, Jéské Couriano, Kasaalan, Keegscee, Kernoz, Kgrad, Kingpin13, Knucmo2, Kotjze, Kuru, LOL, Lacort, Laudaka, LeaveSleaves, LilHelpa,Literaturegeek, Little Mountain 5, Location, Longhair, Looie496, Luiscolorado, Luk, MER-C, MarcoTolo, Marek69, Matt Fitzpatrick, Matthardingu, Maurreen, Maxopath, Mcrasmusson,Mczack26, MegaHasher, Memset, Menchi, Mikael Häggström, Mindgraffiti, Minghong, MissingNOOO, Mlraspetla, Mofocasr, Monkey Bounce, MrJones, Mrzaius, MuRocks, NarSakSasLee,Nastajus, Navious, NawlinWiki, NegativeK, Nevit, Nfwu, Nibuod, Nilmerg, Nonstandard, Notopia, Nsaa, Olamanivelle, Oliverkeenan, Omicron18, Omicronpersei8, OnBeyondZebrax, Onomou,OrgasGirl, Oxymoron83, PT, Pacula, Paintball31390, Paul foord, Pdavide, Peregrine Fisher, Philip Trueman, Phyxius, Piano non troppo, Pinsys, Pmarshal, Pope16, Posix memalign, Posturite,PvsKllKsVp, RDBrown, Rafikk, Ralphyde, Rani Lueder, Rboatright, Redquark, Reepy, Rgoodwin13, Rich Farmbrough, Robin Patterson, Robneild, Roflatwikipediaslamepolicies, Ronz,Root4(one), Rotring, RoyBoy, Sabhlok, Saint70, Sakaton, Sannse, Sarahfisher, Sbyrnes321, Sciencewatcher, Scotteaux, ScoutBird, Senator Palpatine, Sesu Prime, Shoefly, Shutefan, Sietse Snel,Simxp, Skarebo, Smee30, Snigbrook, Snori, Snuffles72, Sonjaaa, SpaceFlight89, Squids and Chips, Stay, StrangeAttractor, Styoung, Susurrus, Swarm, Sylent, Tadpole9, Tango, Tanthalas39,TastyPoutine, Tatterfly, That Guy, From That Show!, The Anome, The Thing That Should Not Be, The sock that should not be, Theblackplague, Thehelpfulone, ThomasNichols, Thunderboltz,Tim Song, Toby Bartels, Tom Edwards, Toph, Umidrb, Unforgettableid, Urod, VKokielov, Versageek, Versus22, Vfrken, Vilefridge, Vquex, Wackymacs, WadeSimMiser, Wangi,WatchAndObserve, Whoopsydaisywikialfisavandal, WiccaIrish, WikiLaurent, WikiSlasher, Winrules, Wiwaxia, Wordsmithing, Wouterstomp, Wtmitchell, Xbspiro, Xe7al, Yamamoto Ichiro,Yock, Zzuuzz, आशीष भटनागर, 731 anonymous edits

Image Sources, Licenses and Contributors 54

Image Sources, Licenses and ContributorsImage:Computer Workstation Variables.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Computer_Workstation_Variables.jpg  License: Public Domain  Contributors: BerkeleyLabImage:Flexible Workplace Variability.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Flexible_Workplace_Variability.jpg  License: Public Domain  Contributors: Unicor.govImage:The speaking portrait.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:The_speaking_portrait.jpg  License: Public Domain  Contributors: Original uploader was Rayray aten.wikipediaImage:Galton at Bertillon's (1893).jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Galton_at_Bertillon's_(1893).jpg  License: Public Domain  Contributors: Fastfission, MuImage:Bertillon - Signalement Anthropometrique.png  Source: http://en.wikipedia.org/w/index.php?title=File:Bertillon_-_Signalement_Anthropometrique.png  License: Public Domain Contributors: Fastfission, MuImage:Anthropometry exhibit.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Anthropometry_exhibit.jpg  License: Public Domain  Contributors: Fastfission, Morio, 1 anonymouseditsImage:Head-Measurer of Tremearne (side view).jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Head-Measurer_of_Tremearne_(side_view).jpg  License: Public Domain Contributors: Fastfission, Pieter Kuiper, 1 anonymous editsImage:IPod Nano 4G black.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:IPod_Nano_4G_black.jpg  License: Trademarked  Contributors: User:AconcaguaImage:Kitchen aid mixer.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Kitchen_aid_mixer.jpg  License: Public Domain  Contributors: Gveret Tered, Majorly, 6ןתיאFile:WesternElectric302.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:WesternElectric302.jpg  License: Public Domain  Contributors: Original uploader was ProhibitOnions aten.wikipediaImage:Fendersrvstratfront.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Fendersrvstratfront.jpg  License: Creative Commons Attribution-Sharealike 2.5  Contributors: Dodek,Drmies, GreyCat, Mrbill, Red Rooster, Wickler, 1 anonymous editsImage:VW 1300 side.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:VW_1300_side.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors: M62File:3-Tastenmaus Microsoft.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:3-Tastenmaus_Microsoft.jpg  License: Creative Commons Attribution-Sharealike 2.5  Contributors:Aka, Darkone, GreyCat, WardenImage:DataHand Professional II Keyboard-Right.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:DataHand_Professional_II_Keyboard-Right.jpg  License: Public Domain Contributors: Getdave, 1 anonymous edits

License 55

LicenseCreative Commons Attribution-Share Alike 3.0 Unportedhttp:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/