Chapter 6Chapter 6

The Process of Interaction DesignThe Process of Interaction Design

By:By: Matt BergsteinMatt Bergstein Kevin ClarkKevin Clark Carol LawsonCarol Lawson Angelo MitsopoulosAngelo Mitsopoulos Phil TownsendPhil Townsend

IntroductionIntroduction

Intent of design is to develop a product that helps its users achieve Intent of design is to develop a product that helps its users achieve their goalstheir goals

How can we do this?How can we do this? CH 1 expressed the importance of designing products which aid in CH 1 expressed the importance of designing products which aid in

everyday taskseveryday tasks

Begin by understanding the product (who needs it, how they will use Begin by understanding the product (who needs it, how they will use it, where they will it, where they will use it)use it)

How do we gain this knowledge?How do we gain this knowledge? Involving the user throughout the process of designInvolving the user throughout the process of design

But what about innovative products where the user is less likely to But what about innovative products where the user is less likely to envision its possibilities?envision its possibilities?

Goals of this ChapterGoals of this Chapter

Consider what ‘doing’ interaction design involvesConsider what ‘doing’ interaction design involves

Ask and provide answers for some important questions Ask and provide answers for some important questions about the interaction design processabout the interaction design process

Introduce the idea of a lifecycle model to represent a set Introduce the idea of a lifecycle model to represent a set of activities and how they are relatedof activities and how they are related

Describe some lifecycle models from software Describe some lifecycle models from software engineering and HCI and discuss how they relate to the engineering and HCI and discuss how they relate to the process of interaction designprocess of interaction design

Present a lifecycle model of interaction designPresent a lifecycle model of interaction design

What is Interaction Design About?What is Interaction Design About?

Fields of designFields of design Graphic designGraphic design Architectural designArchitectural design Industrial and Software designIndustrial and Software design

Each has its own interpretationEach has its own interpretation

Oxford’s Def: “(design is) a plan or scheme conceived in Oxford’s Def: “(design is) a plan or scheme conceived in the mind and intended for subsequent execution.”the mind and intended for subsequent execution.”

Designing therefore involves the development of such a Designing therefore involves the development of such a plan or scheme, and for it to execute, it has to be plan or scheme, and for it to execute, it has to be informed with knowledge about its use and the target informed with knowledge about its use and the target domain. (Ex: multi-level roads)domain. (Ex: multi-level roads)

Interaction DesignInteraction Design

User-centered approach (users’ concerns direct User-centered approach (users’ concerns direct development)development)

Trade-offs and balancing (Ex: Road) Trade-offs and balancing (Ex: Road)

Evaluation and alternate solutionsEvaluation and alternate solutions

Marc Rettig “To get a good idea, get lots of Marc Rettig “To get a good idea, get lots of ideas”ideas”

Brainstorming stimulates innovation Brainstorming stimulates innovation

Communicating Interaction Design Communicating Interaction Design

Communication is keyCommunication is key

Must express clearly to allow review, Must express clearly to allow review, revision, and improvementrevision, and improvement

Ways to communicate:Ways to communicate: Series of sketches (building plans)Series of sketches (building plans) Description in natural languageDescription in natural language Building prototypesBuilding prototypes

Four Basic Activities of Interaction Design (Intro)Four Basic Activities of Interaction Design (Intro)

Identifying Needs and Establishing RequirementsIdentifying Needs and Establishing Requirements Who target users are and what are their needsWho target users are and what are their needs

Developing Alternative DesignsDeveloping Alternative Designs Conceptual Design – creating a conceptual model of what the Conceptual Design – creating a conceptual model of what the

product doesproduct does Physical Design – detail of the product (color, sound, images, Physical Design – detail of the product (color, sound, images,

menus)menus)

Building Interactive Versions of the DesignsBuilding Interactive Versions of the Designs Allows user to actually interact (not specifically software vers) Allows user to actually interact (not specifically software vers)

Ex: Paper-based (cheap, easy)Ex: Paper-based (cheap, easy)

Evaluating DesignsEvaluating Designs Determining usability and acceptabilityDetermining usability and acceptability

Three Characteristics of Interaction Design Three Characteristics of Interaction Design ProcessProcess

User FocusUser Focus Center of attention in book’s entiretyCenter of attention in book’s entirety Center of Interaction Design ProcessCenter of Interaction Design Process

Specific Usability CriteriaSpecific Usability Criteria Specific usability and user experience goals set at beginning of Specific usability and user experience goals set at beginning of

projectproject Help designers choose between alternative designs and check Help designers choose between alternative designs and check

projects progress as developedprojects progress as developed

InteractionInteraction Allows designs to be refined based on feedbackAllows designs to be refined based on feedback Takes time and must be repeated several timesTakes time and must be repeated several times

Practical IssuesPractical Issues

Questions to be answered before interaction Questions to be answered before interaction design:design:

Who are the users?Who are the users?

What do we mean by needs?What do we mean by needs?

How do you generate alternative designs?How do you generate alternative designs?

How do you choose among alternatives?How do you choose among alternatives?

Who Are The users?Who Are The users?

We need to find out the user’s requirements and needsWe need to find out the user’s requirements and needs

Identifying users:Identifying users:

UserUser – the people who interact directly with the product to – the people who interact directly with the product to achieve a taskachieve a task

Others?Others?

Those who manage direct users, those who receive products from Those who manage direct users, those who receive products from the system, those who test the system, those who make purchasing the system, those who test the system, those who make purchasing decisions, and those who use competitive products. (Holtzblatt and decisions, and those who use competitive products. (Holtzblatt and Jones 1993)Jones 1993)

Categories of user (Eason 1987):Categories of user (Eason 1987): Primary – hands-on users of the systemPrimary – hands-on users of the system Secondary – occasional usersSecondary – occasional users Tertiary – those affected by system or influence its purchase.Tertiary – those affected by system or influence its purchase.

Who Are The Users?Who Are The Users?

StakeholdersStakeholders – wide collection of people who all have a – wide collection of people who all have a stake in the development of a successful productstake in the development of a successful product

Includes:Includes: Development team and their managersDevelopment team and their managers Direct users and their managersDirect users and their managers Recipients of the product’s outputRecipients of the product’s output People who may lose their jobs because of the introduction of the People who may lose their jobs because of the introduction of the

new productnew product

Conclusion:Conclusion: Very wide rangeVery wide range Don’t include all of themDon’t include all of them Be aware of who you’re affectingBe aware of who you’re affecting

What Do We Mean By “Needs”?What Do We Mean By “Needs”?

Not just “what do you need”?Not just “what do you need”?

Approach:Approach: Characteristics and capabilities of usersCharacteristics and capabilities of users What they are trying to achieveWhat they are trying to achieve How they currently achieve itHow they currently achieve it Would they achieve goals more effectively if supported differentWould they achieve goals more effectively if supported different

Target group must be consulted, not what you would likeTarget group must be consulted, not what you would like

New innovations require cultural change in target New innovations require cultural change in target populationpopulation

How Do You Generate Alternative Designs?How Do You Generate Alternative Designs?

Common human tendency is to stick with something that Common human tendency is to stick with something that we know workswe know works

We end up overlooking good alternatives, which is a We end up overlooking good alternatives, which is a crucial step in the design processcrucial step in the design process

Where do alternative ideas come from?Where do alternative ideas come from? Cross-fertilization of ideas from different applicationsCross-fertilization of ideas from different applications Evolution of an existing product through use and observationEvolution of an existing product through use and observation Straightforward copying of other, similar productsStraightforward copying of other, similar products

Therefore, it helps to deliberately seek out suitable Therefore, it helps to deliberately seek out suitable sources of inspirationsources of inspiration

Design ProcessDesign Process

Under some circumstances, the scope to consider alternative Under some circumstances, the scope to consider alternative designs may be limiteddesigns may be limited

Design is a process of:Design is a process of: balancing constraintsbalancing constraints constantly trading off one set of requirements with anotherconstantly trading off one set of requirements with another drawing on the designers own experiencesdrawing on the designers own experiences

The constraints may be such that there are very few viable The constraints may be such that there are very few viable alternatives availablealternatives available

Upgrades to an existing system may or may not keep familiar Upgrades to an existing system may or may not keep familiar elementselements

Design Examples:Design Examples:

If designing a software system to run under the Windows operating If designing a software system to run under the Windows operating system, then elements of the design will be prescribed because you system, then elements of the design will be prescribed because you must conform to the Windows “look and feel” and to other must conform to the Windows “look and feel” and to other constraints intended to make Windows programs consistent for the constraints intended to make Windows programs consistent for the useruser

When designing the Windows 95 operating system to replace the When designing the Windows 95 operating system to replace the Windows 3.1 and Windows for Workgroups 3.11 operating systems, Windows 3.1 and Windows for Workgroups 3.11 operating systems, the designers initially focused too much on consistency with the the designers initially focused too much on consistency with the earlier versions (keeping familiar elements)earlier versions (keeping familiar elements)

For designing an electronic calendar, although many software-For designing an electronic calendar, although many software-based applications already existed, paper-based books were a good based applications already existed, paper-based books were a good source of inspiration (for the author of our text)source of inspiration (for the author of our text)

IDEO - A Box Full of IdeasIDEO - A Box Full of IdeasIDEO, an international, innovative product design company, which has been IDEO, an international, innovative product design company, which has been involved in the development of many artifacts including the first commercial involved in the development of many artifacts including the first commercial computer mouse and the PalmPilot Vcomputer mouse and the PalmPilot V

Uses a TechBox, which holds around 200 gizmos and interesting materials Uses a TechBox, which holds around 200 gizmos and interesting materials which are cataloged with more detailed information available via the which are cataloged with more detailed information available via the TechBox’s online catalogTechBox’s online catalog

Staff at IDEO take along a selection of items from the box to brainstorming Staff at IDEO take along a selection of items from the box to brainstorming meetings to be used as visual props or possible solutions to a particular meetings to be used as visual props or possible solutions to a particular issueissue

When items become common place, they are removed from the TechBox to When items become common place, they are removed from the TechBox to make way for the next generation of fascinating contraptionsmake way for the next generation of fascinating contraptions

http://http://ideo.comideo.com

Copying for Inspiration: Is It Legal?Copying for Inspiration: Is It Legal?Copyright:Copyright:

covers the expression of an idea and not the idea itselfcovers the expression of an idea and not the idea itself is free and is automatically invested in the author of something, e.g., the writer of is free and is automatically invested in the author of something, e.g., the writer of

a book or a programmer who develops a program, unless they sign the copyright a book or a programmer who develops a program, unless they sign the copyright over to someone elseover to someone else

Patents:Patents: doesdoes protect the idea rather than just the expression of the idea protect the idea rather than just the expression of the idea there are various forms, each of which is designed to allow the inventor the there are various forms, each of which is designed to allow the inventor the

chance to capitalize on the ideachance to capitalize on the idea unusual for software to be patented, since it is a long, slow and expensive unusual for software to be patented, since it is a long, slow and expensive

processprocess recent trend, however, towards patenting business processes (Amazon has recent trend, however, towards patenting business processes (Amazon has

patented its “one-click” purchasing process)patented its “one-click” purchasing process)

The dilemma comes in knowing when it’s OK to use someone else’s work The dilemma comes in knowing when it’s OK to use someone else’s work as a source of inspiration and when you are infringing copyright or patent as a source of inspiration and when you are infringing copyright or patent lawlaw

http://http://www.loc.govwww.loc.gov/copyright//copyright/http://http://www.uspto.govwww.uspto.gov//

How Do You Choose Among How Do You Choose Among Alterative Designs? Alterative Designs?

Choosing among alternatives is about making decisionsChoosing among alternatives is about making decisions

These decision are made by:These decision are made by: Information gathered about users and their tasksInformation gathered about users and their tasks The technical feasibility of the ideaThe technical feasibility of the idea

Fall into two categories:Fall into two categories: Those about externally visible and measurable featuresThose about externally visible and measurable features Those about internal characteristics to the systemThose about internal characteristics to the system

Examples?Examples?

Why We Concentrate On The Why We Concentrate On The External Factors?External Factors?

Our driving force is the way in which users Our driving force is the way in which users interact with the productinteract with the product

Therefore, we focus on visible and measurable Therefore, we focus on visible and measurable behavior that affect this interactionbehavior that affect this interaction

Internal workings are important only to the extent Internal workings are important only to the extent to which they affect the external behaviorto which they affect the external behavior The tasks that the user will perform should determine The tasks that the user will perform should determine

the designthe design Technical issues should take care of themselvesTechnical issues should take care of themselves

Choosing Between Alternatives – Choosing Between Alternatives – The User-centered ApproachThe User-centered Approach

Let users and stakeholders interact with the Let users and stakeholders interact with the productproduct Discuss their experiences, preference, and Discuss their experiences, preference, and

suggestionssuggestions

This process requires that:This process requires that: The designs are readily available that is reasonable The designs are readily available that is reasonable

evaluated by usersevaluated by users The process is free from technical jargon and The process is free from technical jargon and

complicated notationscomplicated notations

Choosing Between Alternatives – Choosing Between Alternatives – DocumentationDocumentation

Uses a description of how something will Uses a description of how something will work or a diagram showing its componentswork or a diagram showing its components

Downsides to this approach:Downsides to this approach: Uses a static depiction for dynamic behaviorUses a static depiction for dynamic behavior Doesn’t communicate what the product will Doesn’t communicate what the product will

actually be like to the usersactually be like to the users

Choosing Between Alternatives – Choosing Between Alternatives – PrototypingPrototyping

Involves producing a limited version of the product in Involves producing a limited version of the product in order to answer specific questions about the design and order to answer specific questions about the design and feasibilityfeasibility

Used to overcome potential client misunderstandings Used to overcome potential client misunderstandings and to test the technical feasibility of a suggested design and to test the technical feasibility of a suggested design and productionand production

Gives a better impression of the user interface than Gives a better impression of the user interface than explanationsexplanations

There are various types of prototyping suitable There are various types of prototyping suitable depending on the stage of development and types of depending on the stage of development and types of information neededinformation needed

Choosing Between Alternatives – Choosing Between Alternatives – QualityQuality

Make a decision based on a perceived level of “quality”Make a decision based on a perceived level of “quality”

This process requires a clear understanding of what is This process requires a clear understanding of what is meant by “quality”meant by “quality”

Downsides to this approach:Downsides to this approach: People have different definitions of what quality isPeople have different definitions of what quality is People have different expectations for qualityPeople have different expectations for quality Many projects have different stakeholder group, each who can Many projects have different stakeholder group, each who can

define quality of a different waydefine quality of a different way A clear, concise definition of quality is rarely properly A clear, concise definition of quality is rarely properly

documenteddocumented

Usability EngineeringUsability Engineering

The process of writing down formal, verifiable – and The process of writing down formal, verifiable – and hence measurable – usability criteria is a key hence measurable – usability criteria is a key characteristic of an approach to interaction design called characteristic of an approach to interaction design called usability engineeringusability engineering

This involves specifying quantifiable measures of product This involves specifying quantifiable measures of product performance, documenting them in a usability performance, documenting them in a usability specification, and assessing the product against themspecification, and assessing the product against them

Example:Example: This can be used to make changes to a previous version of a This can be used to make changes to a previous version of a

system based on feedback from results of usability testssystem based on feedback from results of usability tests

Lifecycle Models: Showing How Lifecycle Models: Showing How The Activities Are RelatedThe Activities Are Related

A lifecycle model is used to capture a set of A lifecycle model is used to capture a set of activities and how they are relatedactivities and how they are related

More sophisticated models also incorporate a More sophisticated models also incorporate a description when and how to move from one activity description when and how to move from one activity to the nextto the next

They are popular because they allow for an They are popular because they allow for an overall view of the development effort so that overall view of the development effort so that progress can be tracked, deliverables specified, progress can be tracked, deliverables specified, resources allocated, and targets setresources allocated, and targets set

Lifecycle Models cont’dLifecycle Models cont’d

No matter how complex, any lifecycle model is a No matter how complex, any lifecycle model is a simplified version of realitysimplified version of reality

It is an abstraction that only includes that It is an abstraction that only includes that amount of detail needed for the task at handamount of detail needed for the task at hand Additional details will be needed to actually put a Additional details will be needed to actually put a

lifecycle model into practicelifecycle model into practice

Many different types of these models are Many different types of these models are availableavailable Some based on the software engineering and HCI Some based on the software engineering and HCI

modelsmodels

A Simple Lifecycle Model For A Simple Lifecycle Model For Interaction DesignInteraction Design

Please refer to the model on page 186 in Figure 6.7Please refer to the model on page 186 in Figure 6.7

This model incorporates iteration and encourages a user This model incorporates iteration and encourages a user focusfocus

This model is not intended to be prescriptiveThis model is not intended to be prescriptive

It includes the following steps:It includes the following steps: Start with identifying needs and requirementsStart with identifying needs and requirements Alternative designs are generated based on the requirementsAlternative designs are generated based on the requirements Interactive versions of the designs are developed and evaluatedInteractive versions of the designs are developed and evaluated The team gets feedback and determines whether or not to The team gets feedback and determines whether or not to

continue or iterate backcontinue or iterate back The final product will emerge in an evolutionary fashionThe final product will emerge in an evolutionary fashion This process may vary from product to productThis process may vary from product to product

Lifecycle Models In Software EngineeringLifecycle Models In Software Engineering

Before the waterfall method was proposed in 1970, there Before the waterfall method was proposed in 1970, there was no agreed upon approach to software development. was no agreed upon approach to software development.

Since, many lifecycle models have come about: Since, many lifecycle models have come about: The waterfallThe waterfall The SpiralThe Spiral Rapid Applications Development (RAD)Rapid Applications Development (RAD)

These were chosen to be discussed because they These were chosen to be discussed because they represent models used successfully in industry and they represent models used successfully in industry and they show how the emphasis in software development has show how the emphasis in software development has gradually changed to include a more iterative, user-gradually changed to include a more iterative, user-centered view. centered view.

The Waterfall Lifecycle ModelThe Waterfall Lifecycle Model

First Known ModelFirst Known ModelLinear ModelLinear Model Each step must be Each step must be

completed before completed before moving on next stepmoving on next step

Some feedback shown to Some feedback shown to be useful, but idea of be useful, but idea of iteration was not iteration was not embedded in the model embedded in the model and the opportunity to and the opportunity to review and evaluate with review and evaluate with users users was not built into was not built into this model. this model.

Spiral Lifecycle ModelSpiral Lifecycle Model

Suggested by Barry Boehm, 1988Suggested by Barry Boehm, 1988Two main features: Two main features: Risk AnalysisRisk Analysis PrototypingPrototyping

Incorporates them in an iterative framework so Incorporates them in an iterative framework so that ideas and progress are repeatedly checked that ideas and progress are repeatedly checked and evaluated. and evaluated. Explicitly encourages alternatives to be Explicitly encourages alternatives to be considered.considered.Identifies and controls risk.Identifies and controls risk.

Spiral Lifecycle ModelSpiral Lifecycle Model

Rapid Applications DevelopmentRapid Applications Development

User-centeredUser-centered

Minimized risk caused by requirement changing Minimized risk caused by requirement changing during the course of the projectduring the course of the project

Two key features:Two key features: Time-boxing: Time-limited cycles of approximately six Time-boxing: Time-limited cycles of approximately six

months, at the end of which a system or partial months, at the end of which a system or partial system must be delivered.system must be delivered.

JAD Workshops: (Joint Application Development) JAD Workshops: (Joint Application Development) workshops where users and developers come workshops where users and developers come together to thrash out the requirements of the system.together to thrash out the requirements of the system.

Rapid Applications DevelopmentRapid Applications Development

Popularity of RADs has Popularity of RADs has led to industry standard led to industry standard method called DSDM.method called DSDM.

Five phases to DSDM: Five phases to DSDM: Feasibility Study, Feasibility Study, Business study, Business study, functional model iteration, functional model iteration, design and build iteration, design and build iteration, and implementation.and implementation.

Rapid Applications DevelopmentRapid Applications Development

No order of activities.No order of activities.

Activities are highly interconnected. Activities are highly interconnected.

Evaluation is central to model.Evaluation is central to model.

Usability Engineering LifecycleUsability Engineering Lifecycle

Provides a holistic view of usability engineering and a Provides a holistic view of usability engineering and a detailed description of how to perform usability tasksdetailed description of how to perform usability tasks

Three tasks involved:Three tasks involved: Requirements AnalysisRequirements Analysis Design/Testing/DevelopmentDesign/Testing/Development InstallationInstallation

Includes the style guide as a mechanism for capturing Includes the style guide as a mechanism for capturing and disseminating the usability goals of the projectand disseminating the usability goals of the project