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Accessibility issues in Interactive TV – a Dundee perspective

David SloanDigital Media Access GroupDivision of Applied ComputingUniversity of Dundee

Dr Alex CarmichaelDivision of Applied ComputingUniversity of Dundee

{dsloan, acarmichael}@computing.dundee.ac.uk

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Introduction

• Accessibility of iTV to disabled people:

– A Dundee perspective?

• What are the issues? What can we do?

• Focus on older users and iTV

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Applied Computing, University of Dundee

• Centre of excellence since 1980 in research into information and communication systems for disabled and elderly people

• Projects working with non-speaking people, visually impaired people, people with dyslexia, people with Alzheimer’s disease

• Focus on elderly people and technology: Utopia

• Pioneered ‘ordinary users/extraordinary environments

• Digital Media Access Group

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Accessibility and Technology

• Web/software accessibility now relatively high profile

– W3C Web Accessibility Initiative, RNIB, DDA

• Designers/clients know it’s important

• Designers (think they) know what to do

• A culture of accessibility and standards compliance is beginning to develop…

• …in tandem with attractive design

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What’s different about iTV?

• The role of assistive technology

– Not an add on, as with a PC

– Part of the functionality of the Set Top Box (STB)

• Demands of setting up an STB

• Demands/limitations of a remote control device

• The need for accessibility features to be compatible with multiple person viewing

• Analogue switch-off and implications of DDA

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Accessibility barriers to iTV (1)

• Physical impairment– Ability to set up STB

– Manual dexterity: manipulation of remote control

• Sensory impairment:– Can’t see the content of the screen, or labels on

remote control/STB

– Impaired vision affecting perception of screen content screen: text, colour…

– Can’t hear sound/speech

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Accessibility barriers to iTV (2)

• Cognitive impairment– Comprehensibility of instructions: paper and on-

screen

– Concept of Electronic Programme Guide (EPG) (‘tab and go’)

– Other conventions & metaphors

• Combinations of the above– Tend to have greater impact than the sum of

each in isolation

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An accessible iTV system?

• The STB– Clear instructions, available in multiple formats– Easy to install/easy to get someone to do it for you

• The remote control– Robust, operable even with impaired dexterity

• The EPG– Available – and usable - in audio format?– User control: font size, style and colour, and

background colour?– Possible route to accessible iTV content

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Accessible iTV content

• Programmes

– Option to display captions (called ‘subtitles’ in the UK!)

– Option to hear Audio description

– Signing as an alternative to textual captions

• Textual content

– User control over font size, type, colour, background colour

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Multiple Access Need/Multiple conflicts?

• But applying accessibility solutions can introduce new issues…

– ‘Assistive’ technology (substitute ‘lost’ modality/channel)-V-

– ‘Usable’ technology (address limits in all modalities/channels)

• …consider older people and iTV systems

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Elderly not a distinct population

• Older people tend to have multiple minor impairments/disabilities

• Thus some requirements overlap with ‘disabled’ population

• But many requirements also overlap with ‘normal’ (young!) population

(particularly in non-work setting)

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Overlap of ‘poor vision’

• Elderly & VIP have difficulty with text based Electronic Programme Guide (EPG)

• The VISTA Project – developed a speech based interface to satisfy ‘poor vision’ requirement

• BUT:– Elderly also have ‘poor hearing’ (TTS output) and so

need redundancy (in visual modality; text, lip reading)– Elderly also have ‘poor memory’ and so need more

‘navigation support’ (prompts & reminders)

• These aspects not required by VIP but add to cost

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Overlap with ‘average’ population• Many see elderly as a distinct population from

‘average’ (i.e. effectively part of ‘disabled’) & therefore they require ‘assistive’ technology

• But this is (mostly) due to:– an erroneous over-emphasis on the ‘average’

meaningfully describing the population– much HF work based on;

• non-elderly, non-impaired people (often undergraduates)

• implicit assumptions about ‘work’ setting– No distractions– Near optimum performance levels

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Common assumption made about“Age Related Declines”

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Common assumption -v-what tends to be found

Age

Per

form

ance Maximum

Mean

Minimum

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Accommodate people’s diversity• Diversity of young is (effectively) a sub-set of diversity

of elderly (albeit at ‘more able’ end)

• Therefore wider population better served by design that accommodates the diverse abilities of that group, rather than design that caters to a notional ‘average’

• Particularly if ‘average’ = ‘elite’ (at near-optimum performance, in near-optimum setting)

• Should ‘entertainment technology’ require near-optimum performance from anyone!

e.g. distractions, late night, ill, ‘tired and emotional’, etc.

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Communications Act 2003

• Gives Ofcom responsibility to ensure;

“…that domestic electronic communications

apparatus is developed which is capable of

being used with ease, and without modification,

by the widest possible range of individuals

(including those with disabilities)…”

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Conclusion• Design of usable technology must be based on the

range of abilities present in the population

• Addressing such diversity will produce ‘inclusive’ rather than ‘exclusive’ designs

• Need for ‘assistive’ technology likely to remain– Minorities with ‘lost’ modalities/channels– Questions of compatibility/connectivity– Some ‘assistive’ solutions could become mainstream

iTV can be accessible; more research needed