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Accessibility

This briefing sheet is created to help, web designer, developers and decisions makers produce web sites that include considerations for disabled users. In many countries (including the UK) this is a legal as well as a moral requirement. The information presented here is not exhaustive but freely presented to start help the considerations.

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What is Accessibility?

“Accessibility involves making allowances for characteristics a person cannot readily change”

Joe Clark [http://joeclark.org/book/sashay/serialization/Chapter04.html accessed: 9th September 2005]

“..easy to use”

Disability Rights Commission [Making websites that are easyfor everyone to use 200 http://www.drc-gb.org/publicationsandreports/ERFIWebcomplete.pdf accessed: 9th September 2005]

“Equality is a misnomer. Equivalency is the goal”

Joe Clark [Building Accessible Websites 2002 http://joeclark.org/book/sashay/serialization/AccessManifesto.html accessed: 9th September 2005]

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Legislation - Defining Disability

Disability Discrimination Act1995

“A disability is a “physical or mental impairment which has a substantial and long-term adverse effect on his abilityto carry out normal day-to-day activities”

[http://www.opsi.gov.uk/acts/acts1995/1995050.htm]

“It is unlawful for a provider of services to discriminate against a disabled person”

[http://www.opsi.gov.uk/acts/acts1995/1995050.htm]

You can find out more at

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Disability Types

Disability comes in all shapes and forms, many of us will experience disability either permanently or temporarily as various points in our lives.

The following groupings are not exhaustive, are my own definitions and are often interrelated e.g. deaf people may also have associated speech problems.

A very useful site for general disability information is http://www.disability.gov.uk/.

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Cognitive

These are the most common disabilities and centre around a difficulty in processing information and sometimes acting on it e.g. poor co-ordination.

More information on cognitive issues can be found on the Web Aim site http://www.webaim.org/techniques/cognitive/.

Types

  • Dyslexia is the most common, about 1 in 10 will have some form of Dyslexia
  • Attention Deficit Disorder Brain Injuries

Cognitive difficulties are best overcome in web design by multi sensory delivery.

  • Thoughtful Layout
  • Clear Language
  • Text and images
  • Sound and Vision e.g. careful use of Flash and video

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Senses

The two main senses that may affect a user’s access to your web site are Hearing and Sight

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Hearing

Sound is becoming more common place on the web and designers and developers need to be aware. The RNID provides lots of
useful resources.

  • For many deaf people English will be their second language as they use primarily Sign Language
    • Using clear, plain language will assist not only them but also the many non-disabled users (within the UK) for whomEnglish is also their second language
  • Make sure that warnings and information are not given in audio only

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Vision

Majority of visual difficulties are impairment rather than full blindness. Many visual impaired users will probably use a mix of navigation e.g. Screen Readers, magnifiers,
Braille readers. The RNIB provides a wealth of resources about vision impairment.

  • The Blind experience of your web site will be linear
    • This makes good information architecture crucial
  • If you cannot test your site with a screen reader then use something like Webbie to show how screen reader constructs your site.
  • Text-only versions of the site, will increase your work load if you use poor content management
    • Careful page structuring supported by Cascading Style Sheets should avoid the need for Text-onlyversions
  • Movie files may need audio descriptions
  • Alt attribute descriptions need to be meaningful

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Speech

Interactive speech is not a dominate factor on the web at the moment but it is becoming important as the Voice over Internet Protocol market grows and expands.

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Motor

The mouse is not the only input device there are alternative inputs e.g. trackballs, touch screens, head pointers and mouse keys. Many interfaces over rely on the
user being dextrous with a mouse e.g. some DHTML menus.

WebAim provide a useful summary of some of the alternative interaction that user might call upon http://www.webaim.org/techniques/motor/assistive.php.

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Websites Standards

The World Web Consortium is the controller and best source for detail on actual web standards.

It is important that principles such as separating style and content and are followed by using tools such as Cascading Style Sheets.

In summary

  • Use XHTML/HTML for structure and free content contributors
  • Use Cascading Style Sheets for the look an feel
    • If properly structured your site will degrade gracefully with older browsers and can provide a look for alternative media e.g. mobile screens
  • Use Client-Side Scripting for behaviour but reinforce it with Server-Side alternatives
  • Use automatic validation but do not rely on it

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Accessibility Validation

Accessibility validation cannot be done using automated tests alone (The Web - Access and Inclusion for Disabled People 2004). There are variations but most automated
validation is done against World Wide Web Accessibility Initiative Guidelines.

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Know your audience

Knowing your audience is really important when considering your website. By considering the disabled in web design we may improve the design for all [The Web - Access and Inclusion for Disabled People 2004).

There are all sorts of sources of information, which can help build up a profile of users. A few are.

  • Usability study
  • Marketing Surveys
  • Server Statistics

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This document provides notes for the presentation first given by Stuart Smith to the Usability Professional Association Northern Meeting on 14th September 2004.

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