Human computer interaction

Dr. Andy Seddon, [email protected]

StaffordshireUNIVERSITY

Schoolof

Computing

Human computer interaction

Eur Ing Roger FairheadBSc CEng MIET MAPM MICG

With thanks to:



Schoolof

Computing

Content

What is the human-computer interface?

The human The computer Interaction User interfaces Interface design



Schoolof

Computing

What is HCI?

HCI isthe study of people, computer

technologyand the ways these influence each

other

HCI adds design principles for computer screens and the human computer dialogue



Schoolof

Computing

Goals of HCI

The goals of HCI are to produce systems which are: usable safe functional effective efficient



Schoolof

Computing

Why is HCI important?

A lack of a good user interface will often mean that software is often difficult and tedious to use.

A good interface will help to achieve higher productivity increased safety



Schoolof

Computing

Who contributes to HCI?

Research into HCI combines expertise from many areas

– computer science– psychology (cognitive and social)– ergonomics– linguistics– artificial intelligence– engineering and design



Schoolof

Computing

The human (1)

Input provides a human withinformation that can be used tocomprehend its surroundings

Output allows a human tointeract with and influence its

surroundings



Schoolof

Computing

The human (2)

Memory is a human withinformation that can be used tocomprehend its surroundings

Three types of human memory– sensory– short-term– long-term



Schoolof

Computing

The human (3)

short term

sensory

long term

Input

Attention

RehearsalRecall



Schoolof

Computing

The computer

Input provides the computer withinformation that its program needs

to ‘solve’ a problemOutput allows the computer to

communicate the results of itsprocessing to the user



Schoolof

Computing

Interaction

Interaction can be achieved using a number of styles

» command entry» menus and navigation» forms and spreadsheets» question and answer dialogue» natural language dialogue» WIMP» direct manipulation



Schoolof

Computing

User interfaces

An interface can refer to the physical connection between two pieces of hardware.A user interface refers to:the way people (users) interact with a computer: how they tell it what to

do, and how the computer communicates a response or result



Schoolof

Computing

Interfaces types (1)

Command line interface– type in commands– need to know syntax and command

names Natural language processing

– type in commands in user’s natural format

– sentences, abbreviations used



Schoolof

Computing

Interfaces types (2)

Menu-driven interface– learning time reduced– option is chosen and computer carries

out appropriate sequence of commands

Graphical user interface (GUI)– command/menu approaches are text

based– GUIs use icons as well as text– pointing device used



Schoolof

Computing

Interface design (1)

Interface design is not independent of program design.Need a model of the user, which requires understanding of:

– types of users– user’s requirements– user’s level of ability



Schoolof

Computing

Interface design (2)

Considered along with the model of the user:

screen design controls user guidance error messages response time



Schoolof

Computing

Usability

Three categories of principles to determine usability of an interface learnability flexibility robustness



Schoolof

Computing

Web Design Principles (WAI)

Accessibility

The Web Accessibility Initiative (WAI) develops strategies, guidelines, and

resources to help make the Web accessible to people with disabilities



Schoolof

Computing

Web Design Principles (WAI)

The power of the Web is in its universality.

Access by everyone regardless of disability is an essential aspect.

Tim Berners-Lee, W3C Director and inventor of the World Wide

Web



Schoolof

Computing

Web Design - Accessibility

The needs that Web accessibility aims to address include:– Visual– Motor/Mobility– Auditory– Seizures– Cognitive/Intellectual

http://en.wikipedia.org/wiki/Web_accessibility

http://en.wikipedia.org/wiki/Web_accessibility



Schoolof

Computing


Visual impairments including blindness, various common types of low vision and poor eyesight, various types of color blindness;



Schoolof

Computing


Motor/Mobility: e.g. difficulty or inability to use the hands, including tremors, muscle slowness, loss of fine muscle control, etc., due to conditions such as Parkinson's Disease, muscular dystrophy, cerebral palsy, stroke;



Schoolof

Computing


Auditory: Deafness or hearing impairments, including individuals who are hard of hearing;



Schoolof

Computing


Seizures: Photoepileptic seizures caused by visual strobe or flashing effects.



Schoolof

Computing


Cognitive/Intellectual: Developmental disabilities, learning disabilities (dyslexia, dyscalculia, etc.), and cognitive disabilities of various origins, affecting memory, attention, developmental "maturity," problem-solving and logic skills, etc.;



Schoolof

Computing

Principles of effective Web design

Don’t make users think Don’t squander users’ patience Manage to focus users’ attention Strive for feature exposure Make use of effective writing

http://www.smashingmagazine.com/2008/01/31/10-principles-of-effective-web-design/





Schoolof

Computing

Principles of effective Web design

Strive for simplicity Don’t be afraid of the white space Communicate effectively with a

“visible language” Conventions are our friends Test early, test often






Schoolof

Computing

Some links

Web page accessibility checker

http://www.webpagesthatsuck.com/

http://www.rnib.org.uk/professionals/webaccessibility/Pages/web_accessibility.aspx






Human computer interaction

Documents

Transcript of Human computer interaction