The People-Technology System

IMD07101: Introduction to Human Computer InteractionBrian Davison 2011/12

With material from Tom McEwan

Content

• What is a system?• Socio-technical success factors

– Usability– Acceptability– Engagement– Accessibility

What is a system?

• Examples

• An set of elements standing in interrelations

Generic systems• Generic = describing a whole class

– Opposite of specific

• Natural systems• Human-made systems• Social systems

• Socio-technical systems

Technology

People Organisation

Ludwig von Bertalanffy• General systems theory (1968)

– Goal/purpose

Environment

System boundary

Input OutputThroughput

Success factors• Usability

– The quality of the interaction – e.g. time taken to perform tasks, number of errors made, the time needed to become a competent user.

• Acceptability – The “fitness for purpose” in the “context of use”. – Also: personal preferences that contribute to users “taking to” an artefact, or not.

• Engagement – Designing for great, exciting and riveting experiences.

• Accessibility– Removing the barriers that exclude some people from using the system at all.

• Often summarised as “design principles” or “values”

Usability• Usable systems are

– Efficient – you can turn your effort into results– Effective – has what you need and is well-organised– Easy to learn and remember how to use– Safe to use– Useful – high utility to do the things you need done

• Usable, useful, used• Don Norman

– Gulf of Execution: difference between what you want to do (your goal) and what you have to do (with the system)

– Gulf of Evaluation: difference between what the system tells you, and your understanding it

Acceptability• Politics

– Will groups in the organisation find your design unacceptable? eg changing the balance of power

• Convenience– Does your design fit into what people are trying to do?

• Culture and society– Does your design go against aspects of lifestyle that people value?

• Usefulness– It might be easy to use and full of desirable features, but can you check your

schedule while talking to someone on the phone, for example?

• Economics– Can people afford it? Will suppliers maintain it? e.g. the history of MP3

Engagement• Shedroff:

– Identity – reinforces our identities (eg Mac v PC)– Adaptivity – can be used with different situations/skill levels– Narrative – a good story– Immersion – total engagement– Flow – smooth movement

• Designing for “pleasure”

Accessibility• This is not just political correctness• “The World Health Organisation in 1976 drew distinctions between

– impairment (which is part of an individual), – disability (contrasting the individual’s abilities with those of society as a whole) and – handicap (society’s accommodation of people with an impairment).

• Thus both “disability” and “handicap” are societal constructs – a consequence of a flawed attempt to understand the user’s context.

• We must choose whether or not to discriminate against, or exclude, other people.

• McEwan, T., Anderson, A., Bartholomew, C., Clarke, P, & Morrison, A. (2003) Learning about universal access. In P. Gray, & H. Johnson, (Eds), Designing for Society, proceedings of the 17 th British HCI Group conference HCI2003 (September8-12, 2003) Volume II. Swindon: BCS

• World Health Organization. (1976) Document A29/INFDOCI/1, Geneva, Switzerland.

Incidence of Impairments in the EU

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85

1

Reduced co-ordination

Reduced strength

Cannot use one arm

Cannot use fingers

Intellectually impaired

Dyslexic

Language impaired

Speech impaired

Low vision

Blind

Hard of hearing

Profoundly deaf

Walks with aid

Wheelchair user

In 2002, 16% of men and women aged 16-64 in the EU report a long-standing health problem or disability. (http://ec.europa.eu/social/BlobServlet?docId=3008&langId=en , p10)

Gill (1997) lists the following incidence (in millions)

Blurred distinctions• In fact, accessibility refers to us all• There are things we do better or worse than the person sitting beside

us– This is because we have a range of capabilities– We have a range of physical attributes – We have a range of mental abilities– We have “talent”

• After the age of 25, we are all gradually losing ability, and abilities don’t vanish, they fade.– Mosquito? http://www.jetcityorange.com/mosquito-ringtone/mosquito-ringtone.mp3

• There are also environments where we are less able to use technology. – Can you suggest any?

Users' capabilities• Office of National Statistics

survey 1997• i~design project at

Cambridge University

• 7 capability categories– Vision– Hearing– Thinking– Communication– Reach and stretch– Dexterity– Locomotion

Waller et al. (2010) Using disability data to estimate design exclusion. Universal Access in the Information Society 9:195–207

eg. dexterity• D1 Cannot pick up and hold a mug of coffee with either hand

• D4 Cannot pick up a small object such as a safety pin with either hand

• D8 Has difficulty wringing out light washing or using a pair of scissors

• D11 Can pick up a small object such as a safety pin with one hand but not with the other. Can pick up and carry a pint of milk with one hand but not the other. Has difficulty tying a bow in laces

• D12 Full dexterity ability

Environmental issues• Designers need to focus on the demands their designs make on

people’s abilities. • Is there much difference between

– an ordinary user in an extraordinary environment (under stress, time pressures, etc.)

– an extraordinary user (e.g. a user with an impairment) in an ordinary environment.

• People and Context

Types of exclusion• Physical

– inappropriate location of equipment– input and output devices making excessive demands on their abilities.

• Conceptual– people may be excluded because they cannot understand complicated instructions

or obscure commands– they cannot form a clear mental model of the system.

• Economic– people are excluded if they cannot afford some essential technology.

• Cultural– making inappropriate assumptions about how people work and organise their lives.

• Social– equipment is unavailable at an appropriate time and place

Short break

A model for (relative) ignorance!

Source: Will Taylor, NCNM, Oregon, USA - http://www.businessballs.com/consciouscompetencelearningmodel.htm

Removing barriers to access

• Universal design– Eliminates need for “special features”– Fosters individualisation and end-user acceptability– Does not imply a single solution for all users– Suits the broadest possible end-user population– Different solutions for different contexts of use

• Inclusive design• Design for all

Principles of Universal Design

• Equitable use– Don’t disadvantage or stigmatize any

group of users.

• Flexibility in use– For a wide range of individual

preferences and abilities.

• Simple, intuitive use– Easy to understand, regardless of the

user's experience, knowledge, language skills, or current concentration level.

• Perceptible information– User gets necessary information,

regardless of ambient conditions or the user's sensory abilities.

• Tolerance for error– The design minimizes hazards and

the adverse consequences of accidental or unintended actions.

• Low physical effort– The design can be used efficiently

and comfortably, and with a minimum of fatigue.

• Size and space for approach & use– You can approach, reach,

manipulate, and use, regardless of your body size, posture, or mobility

Inclusive design toolkit

Inclusive design toolkit

http://www.inclusivedesigntoolkit.com/

Why bother with Accessibility?

• Legal/Ethical

• Political: http://ec.europa.eu/social/main.jsp?catId=429&langId=en

• Solutions: UN and W3C have relevant declarations and guidelines. – Ignore WCAG2.0 at your peril http://www.w3.org/TR/WCAG/

Why bother with Accessibility?Charge:

In 2000 the Sydney Organising Committee for the Olympic Games (SOCOG) was sued for having an inaccessible web site by a visually-impaired user who was unable to access ticketing information, event schedules or postings of event results.

Verdict:

The court determined that the complaint was correct and SOCOG was found guilty of breaching the Disability Discrimination Act and fined $20,000.

Automated readers• Web authors write mainly for the 90% who are able-bodied.• But – 80% of referrals to web pages come from search engines• Search engines use an indexing robot to crawl the pages.• The indexing robot is BLIND – it can only read text.

– It also has a number of verbal and spatial reasoning limitations

• Professional spammers use software which will automatically create an email account, and then use it to send spam until the ISP closes down the account

Humans only• Completely • Automated • Public • Turing test to tell • Computers and • Humans • Apart

• http://webinsight.cs.washington.edu/projects/audiocaptchas/

Design Principles (Benyon p.90)• Access, Learn and Remember

– Visibility– Consistency– Familiarity– “Affordance”

• A Sense of Control– Navigation– Control – Feedback

• Safety and Security– Recovery– Constraints

• Suitable– Flexibility – Style – Conviviality