Assistive Technology and Inclusive Design

I) Introduction

Concern here is with attempting to use technology to help users who are disabled. GOW

AKA rehabilitation technology

AKA extraordinary HCI

What exactly “disabled” means is a controversial issue

Eg recent criticisms of the “medical model” of disability (eg Bishop 2003 p 549)

The social model of disability (eg Shaw 2000) is often seen as more appropriate – “while people have impairments, the environment – attitudinal as well as physical – can be disabling”.

Edward’s reading (1995) of the WHO classification:

impairment - “any loss or abnormality of psychological, physiological or anatomical structure or function”

disability - “any restriction or lack (resulting from an impairment) of ability to perform an activity in the manner or within the range considered normal for a human being”

handicap - “a disadvantage for a given individual, resulting from an impairment or disability, that limits or prevents [their] fulfilment of a role”

so, impairment disability handicap vision seeing use of GUI

or impairment handicap memory loss use of Unix

Compare UK DDA - Disability Discrimination Act (1995) – a disabled person is someone who has a physical or mental impairment, which has an effect on his or her ability to carry out normal day to day activities. That effect must be substantial, adverse and long-term.

Much controversy in the area, eg re the DDA: “all of the terms used in the definition … have been challenged in court” (Riddell et al 2002)

Hence Moore’s motto for level 6 work:

The more we pursue knowledge, the less we know

The challenge is to support the differing needs of people with (and without) these impairments.Not easy:

physical and visual - main problem = computer I/Ohearing and cognitive - main problem = communication and language

needs may varye.g. GUI - poor for visual impairments, preferred by other user groups

cf. Edwards - “kerb cut phenomenon” (29)

So - not easy, but are possibilities as well as problems

e.g. great benefit of IT to many disabled people

a “disability ” may have advantages as well as disadvantages, IT may be able to utilise them better

e.g. “Skallagrigg” novel

II) The importance of assistive technologyCan suggest several arguments:

•large number of disabled peopleBT estimate - 10% of populationEU estimate re UK - 5% of people below 30, 30% at 60, 70% at 80 (Edwards)50 million disabled people in Europe (TAP 1997 cf. Dix et al 2004, BCS 2000)exacerbated by demographic trendsmore old people

so - any computer system likely to be used by disabled people, so need to be aware of the issues when designing any interactive system

•economic argument:

most types of jobs use computers

therefore must be usable by disabled people

further - possible worker shortage because of birth-rate trends (Newell)and good interfaces increase productivity

systems that reduce need for intensive nursing care or tuitionwould be very cost effective

•altruistic argumenti.e. a worthwhile endeavour

current interfaces often poor (e.g. ATMs too high, screen cannot be read by visually impaired)

HCI expert may be able to influence the design of new artefactsto cater better for disabled people

•legal argument

“increasingly..... the rights of people with disabilities is being enshrined in legislation” (Newell)

eg DDA,

SENDA (BCS 2000)

must ensure system is legally acceptable

•environmental argument

Newell (2004) – non-disabled people can be handicapped by their environment in the same way as disabled people are

soldier example

need therefore to allow for impairments even if there are no “impaired users”

•offshoot argumentthe argument here is that working with extraordinary HCI can have benefits for “general” HCI research and practice

e.g. Edwards “extra-ordinary users challenge the boundaries of the subject”

Newell - “taking into account extra-ordinary needs produces better and more widely useful design solutions for everyone”

Benyon et al (2005): “if a design works well for people with disabilities, it works well for everyone”.

Spolsky (2000, see http://www.joelonsoftware.com/uibook/chapters/fog0000000064.html, [accessed Feb 2 2009]):

“I don't really believe that people are dolts, but I think that if you constantly try to design your program so that it's easy enough for dolts to use, you are going to make a popular, easy to use program that people like. And you will be surprised by how what seem like small usability improvements translate into lots more customers.”

in particular:may be useful to evaluate systems with disabled peoplemay reveal problems that would otherwise be overlooked

designer is forced into considering individual differences

normative model clearly not appropriate

spin-offs of specific artefacts (Newell):e.g. speech transcription system developed for deaf users now used for transcription in law courtsfuture possibilities:symbol system research may lead to useful info re using icons in HCI

all this is useful because, arguably:

mainstream HCI researchers ...[may have]... too narrow a view of their user population “Most contemporary user interfaces are designed for healthy, young adults” (Leventhal and Barnes 2008: 24)

and conversely, AT people should become more aware of HCI research

Possible counter-arguments re importance of extraordinary HCI :

ExpenseDifficultySize of target population

III) Approaches to Assistive Technology

Essentially there are two possibilities:

a) create specific artefacts for the disabled userusing the technology as “prostheses”

b) adaptation of the interface to existing artefacts to make them more accessible to users with disabilities

adaptationsthe interface between the adaptation and the underlying system is fixed

attempt to adapt the interface it presents to the user, e.g. by providing alternative input devices (see below)

ideally one adaptation will fit several applications (e.g. a spoken front end which works for a word processor and a database system (Edwards))

Edwards cites 3 reasons for using adaptations rather than building new applications from scratch:

data transfer

different preferences amongst the disabled user population

users’ self esteem

may prefer to be seen to be using the same kit

Prostheses

designed for a specific user

therefore no constraints from the target softwaretherefore likely to be less of a user interface problem (end-user variability much less important an issue), but remaining UI issues covered in the module will still be important

Seen the general approaches, consider now differing types of disability.

IV)Visual impairments

Most significant sensory impairment re computer systems given current predominance of VDUs

Need to distinguish between people with partial sight and people who are blind

people with partial sight11.5 million people in Europe with partial sight (TAP 1997, cf. BCS 2000)

evidence suggests they prefer to use their sight rather than an interface designed for blind users (Edwards)

need therefore appropriate aids, e.g.enlargementbut beware - may make some problems, e.g. tunnel vision, worse

better lighting

blind users1.1 million blind people in Europe (TAP 1997)must use touch or hearing or both

touchcomputer generated braillehard copy - printoutA Braille Embosser.soft braille - on the screenBraille chord keyboardskeyboards with marked keys

hearingspeech I/O“screen readers” Cf. “auditory icons” and “earcons”

V) Hearing impairments

Less of a problem than visual

But an increasing problem given the advent of multimedia computing

Early attempts to support sign language output are underway

Text terminals can be used in a prosthetic role for distant communication, e.g. Minicom

VI) Physical impairments

Need considerable motor skill to use current computer technology

Users may have varying degrees of impairment regarding these motor skills

18 million such people in Europe (Howey 1995)

Need therefore to cater for these - very important computer often used to control prosthetic devices, e.g. wheelchair (Edwards)

No part of the body can be used to operate keyboardswitches likely to be used

e.g. operated by suck and puff

eye gaze interfaces being researched

as are “Neural Interface Devices”

No hand use possiblemay use “unicorn stick” (Edwards)

may use speech input, e.g. to control house lights

Hand use possible but impairede.g. hand tremor

plastic keyguard maybe

turn off autorepeat

Goransson (2004) discusses a PDA for people with Parkinson’s diseasekeyboards sized for wide or narrow reachchord keyboards

thinking as a means of input (?!)

prediction software

Speech impairment“augmentative communication”

VII) Cognitive impairments

Four groups of impairments (Edwards):memory problems

perception problems

problem solving impairmentse.g. difficulty in evaluating a proposed solution

conceptual problemse.g. difficulty in generalising learned concepts

Tentative guidelines:simplify language

provide on-line help

keep displays simplee.g. symbols and icons rather than (or well as) textsimplified language

be consistent

speech to support written information (Karlsson)

artificial intelligence and decision support

Cf. Research at Leeds Met re dyslexia (Powell et al 2004) and autism (Moore et al 2005)

VIII) Multimodality and redundancy

One general approach to making interactive systems accessible to people with disabilities is to build in “redundancy” (Dix et al 2004, p. 366f)

“Redundancy” here refers to providing more than one way of doing the same thing.

E.g. graphical information is also available in readable text or speech.

This relies on “multimodal interaction” – it uses more than one mode of interaction.

Thus, some combination of the following should be considered for use:

VisionThe main channel currentlyMany systems WIMP based

Windows, icons, menus, pointers

SoundSpeech recognition

Thus far only “single-user systems that require considerable training” (Dix et al 2004 p. 371)

Speech synthesis

Other sounds

E.g. auditory icons

Touch

Haptic interface

Possibilities for the future: gesture recognition, mind-reading (?!), physiological input-output (e.g. wearable computers).

IX) Universal design

So far, we have had a very interesting look at how we might design interactive systems so that they are more usable by people with disabilities.

Such design is an important aspect of “universal design” – defined by Dix et al (2004, p. 366) as “the process of designing products so that they can be used by as many people as possible in as many situations as possible”.

Universal design involves these areas of human diversity: people with disabilities, older people, children, cultural differences.

Seven general principles of universal design have been proposed:Equitable use – no user is excludedFlexibility in use - design accommodates a wide range

of individual preferences and abilitiesSimple and Intuitive Use - use of the design is easy to

understand, regardless of the user's experience, knowledge, language skills, or current concentration level.

Perceptible Information - the design communicates necessary information effectively to the user, 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 and Use - appropriate size and space is provided for approach, reach, manipulation, and use regardless of user's body size, posture, or mobility.

• More details of the 7 principles at:

http://www.design.ncsu.edu/cud/about_ud/udprinciplestext.htm

[accessed 2.2.09]

Web accessibilityThe concern here is web use by people with disabilities.

Important to make the web accessible to people with disabilities

Eg Mills (2000): disabled people have “among the lowest rates of use of these technologies, and the problem is largely one of access”.

Nielsen - it should be relatively unproblematic if HTML is used correctly – ie to encode meaning rather than appearance. GOW

Specialist browsers can then interpret the meaning appropriately.

Nielsen offers principles to help make web sites more accessible – see appendix (on X-stream).

• The World Wide Web Consortium (W3C) has developed guidelines for web accessibility - http://www.w3.org/TR/WCAG10-TECHS/ [accessed 2/2/09]

• There are 14 guidelines, with a total of 60 checkpoints that must be followed to ensure a site is accessible.

• The checkpoints are broken down into 3 different priority levels.

• Priority 1• A Web content developer must satisfy this

checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use Web documents.

• Satisfying this checkpoint leads to “level A” conformance:

• Priority 2• A Web content developer should

satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing Web documents.

• Satisfying this checkpoint leads to “Double-A” conformance:

• Priority 3• A Web content developer may address this

checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to Web documents.

• Satisfying this checkpoint leads to “Triple-A” conformance:

• Web pages deemed acceptable from the accessibility perspective can apply for “Bobby Approval” and display a “Bobby Approved” logo.

• Bobby is a web-based tool that analyses web pages for accessibility

• It used to be free, but not any more it seems - http://www.cast.org/bobby/ [accessed 27/10/09]

• Such automated approaches have recently been called into question (eg Witt and McDermott 2004)

And the “stamp of approval” cannot meaningfully be policed(?).

X) Summary• Looked at some ways in which IT might promote the

integration of disabled people into society

• Interesting and important area

• Hosam??

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