UCSD AND ADVANCED TECHNOLOGY

Human-computer interaction: users, tasks &

designs

By the end of this lecture you should be able to...

Define & describe the following concepts: Universal access Design for All Customisation Assistive technology Adaptable systems Adaptive systems Self-configurable systems User diversity User modelling Standards and evaluating standards.

Definitions

Useful: system design to ensure that useful functions are included, reflecting the requirements of your users.

Usable: system design to ensure that the functions are presented in such a way that they can be used by users.

Accessible: system design to ensure that system functions can be accessible to users with disabilities or in extreme circumstances.

The numbers of people with disabilities in geographic Europe

Wheelchair user 3 millionCannot walk without aid 45 millionReduced strength 22 millionIntellectually impaired 30 millionHard of hearing 80 millionBlind 1 millionLow vision 11 millionElderly 80 million

Population Changes

In just a few decades, scientific progress has brought about a significant increase in life expectancy in the industrialized countries. But has the quality of life of the elderly improved along with it? As people live longer, medicine is facing a general increase in age-related illnesses, such as Alzheimer's disease and certain kinds of cancer.

RTD info - Magazine for European Research

Correlation of age and disability

Age and disability (Figure 10)

0

10

20

30

40

50

60

70

80

Age 3 8 13 18 23 28 33 38 43 48 53 58 63 68 73 78 83 88 93

Age

Pro

po

rtio

n o

f p

eo

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wit

h d

iab

ility

in %

France (Male)

Germany

The Netherlands

UK

Physical Disabilities

MobilityDexterityReachBalanceStrength and StaminaHeight

Sensory Disabilities

VisionHearingVision and Hearing

Other and Multiple Disability

LearningIlliteracySpeech

Multiple

Real Disabled People

A person with diabetes may have reduced sensitivity in their hands and feet and be blind or partially sighted. Their requirements could include some or all of the requirements for a user with mobility, dexterity and visual impairment.

A person with arthritis may have problems in any of their joints, this means that they may have mobility, dexterity or speech problems.

Medical Model

Disabled people often feel a loss, for all the things they would like to do, but cannot; a loss of goals and dreams that seem unobtainable.

Disabled people often feel they are a burden on family and friends, and a problem for doctors who cannot cure them.

Medical Model

This traditional view of disability is called “the Medical Model of Disability”, because it sees people as medical problems. As a result disabled people are expected to see their impairment as their problem, something they will have to make the best of and accept that there are many things they cannot do.

Social Model

The social model of disability starts from a different perspective. It ignores how “bad” a person’s impairment is. Instead it establishes that everyone is equal and demonstrates that it is society which erects barriers that prevent disabled people participating and restricts their opportunities.

Universal Access

Universal access indicates system design that can be used by anyone, anytime, anywhere.

It involves both suitable design and suitable means of access to a system.

For example, consider an adaptive web browser which translates web sites into appropriate formats.

Design for All

Design for All (Design 4 All) indicates a design or set of designs so that the system can be used by all users, regardless of their strengths & weaknesses, their level of expertise, disabilities and environments.

Design for All includes adherence to design standards to use user accessibility.

For example, consider a word processing application with a number of different design versions.

Customisation

Customisation is the adaptation of an existing system to meet the needs better of a specific user, made by the user or a third party.

For example, this would include changing the set-up of a mouse for a left handed person.

Explore the accessibility options available in Windows.

Assistive Technology

Assistive technology adds to the basic functions to support the performance of users with disabilities or who work in extreme environments.

For example, consider a person with visual impairments or who drives a fast train.

Adaptable Systems

Adaptable systems are those which are able to take in the profile of a user at system onset, in order to adapt to their specific needs and requirements.

For example, this would include a word processing package which presents visual information in different ways for users with different visual impairments.

Adaptive Systems

Adaptive systems are those which can respond to the performance of a user by changing system parameters to enhance user performance.

For example, consider a web browser which responds to the errors of a user by changing the appearance of the information on the screen.

Self-configurable systems (1)

A self-configurable system is one which is able to observe its own status and change its parameters (hardware or software) accordingly.

There are a number of circumstances when this is important.

Self-configurable systems (2)

For example, a system working in a remote or dangerous location (e.g. deep sea bed) cannot be accessed easily by a mechanic.

For example, a computer system being attacked by a virus may need a response that is too fast for a system administrator.

For example, a system might need to respond quickly to the performance problems of a specific user.

User diversity

In user centred design, the role of the user is more central than more traditional methods.

However, user centred design may not pay sufficient attention to user diversity. Variance within a group of users. The existence of distinct groups of users within the

population of users.

User modelling (1)

An appreciation of user diversity can be: Ad-hoc or Systematic.

We can respond passively to user differences or

We can seek to understand user diversity on a systematic basis.

User modelling (2)

In order to understand user diversity on a systematic basis, we could use a user modelling framework.

For example, MHP or Simplex

Model Human Processor

This framework identifies the following parameters within which users can differ:

Perception Cognitive Processes Output (responses) STM LTM

Simplex

This framework identifies the following parameters within which users can differ:

Perception (input) Feedback Output (responses) Output (complex responses sequences) Working memory Emotions Long term memory (data warehouse) Mental models Executive functions

That’s all Folks!