Web accessibility

Encyclopedia : W : WE : WEB : Web accessibility

For Wikipedia's accessibility policy, see [Accessibility].

Web accessibility refers to the practice of making Web pages accessible to people using a wide range of user agent devices, not just standard web browsers. This is especially important for people with disabilities which require such devices to access the Web.

The disabilities that Web accessibility is concerned with encompass users who are:

blind or visually impaired, e.g. various common types of poor eyesight, various types of colour blindness
motor impaired, e.g. Parkinson's Disease, muscular dystrophy, cerebral palsy, stroke
cognitively impaired, i.e. poor short-term memory (as commonly caused by senile dementia), dyslexia
hearing impaired or deaf
non-native speakers of the website's language(s) (including users of sign languages)

Contents

Benefits of Web accessibility

Designing websites with accessibility in mind can often enhance usability for all users; these users also include automated access to the site, such as search engines.

A key to accessibility is to let people access content in their preferred way. This can benefit fully able users as well as those with disabilities: for example, some people may prefer icons and others may prefer text; even fully able people may want to adjust text sizes depending on their viewing circumstances; search engines, like blind people, generally cannot make much use of graphics.

Different sites will require different degrees of concern for accessibility. For example: a site providing information specific to ADHD needs to be easily accessible by people with ADHD; a government site of general interest or a resource directory for people in crisis would need to take into account as many disabilities as possible in order to be available to all citizens.

Many people with visual impairments or dyslexia will want to change the colours of text or the background to make it easier to read. Many people with dyslexia or ADHD will want to stop moving images on the screen whilst they are reading, as they are easily distracted. People with ADHD may also be confused or distracted by link-rich sites: they can have difficulty when presented with so many options.

For example, hyperlinks that can only be followed by clicking on them with a mouse are impossible to use for those who can only use a keyboard or screen reader to interact with their computer. Information provided only in audio format can't be accessed by people who are deaf, and if provided only in graphic format information is invisible to people who are blind.

Screen readers are of only limited use, due to the differences between spoken and written language and the complexity of text, therefore designing sites in accordance with Web accessibility principles is necessary to enable access for all users. A set of guidelines [link] and two accessible[link] web portals designed for people developing reading skills are peepo.com [link] — try typing a letter with your keyboard for more — and peepo.co.uk [link] with enhanced graphics, unique style controls and improved interactivity (requires SVG supported browser).

Technology

User agent devices

The standard Web browser on a PC is the by far the most common type of user agent but there are others. People accessing Web content on a PDA or a mobile phone, or search engines accessing Web content via a web spider are just a few other examples.

People with disabilities use a wide range of devices or technologies to access Web content, these include:

speech or voice browsers
text-only browsers (such as Lynx)

The quest for universal Web accessibility is an attempt to develop Web content so that it is accessibile via all user agent devices for all people.

Assistive technologies

In addition to dedicated Web content user agents, a wide range of assistive technologies are available to help people with computer accessibility. These technologies can greatly assist access to Web content for people with disabilities. Examples include:

Speech recognition software, which can be useful for those who have difficulty using a mouse or a keyboard.
Screen magnification software, which magnifies what is displayed on the computer monitor, making it easier to read for vision impaired users.
Keyboard overlays which can make typing easier and more accurate for those who have motor control difficulties.
Screen reader software, which can read out, using synthesised speech, either selected elements of what is being displayed on the monitor (helpful for users with reading or learning difficulties), or which can read out everything that is happening on the PC (used by blind and vision impaired users).
Refreshable Braille displays, which render text as Braille characters, usually by means of raising dots through holes in a flat surface.

However, in order for these technologies to be fully effective when users are browsing the Web, it is essential that websites are designed to be accessible.

The Web Accessibility Initiative (WAI)

The Web Accessibility Initiative (WAI), part of the World Wide Web Consortium (W3C), was established to oversee the development of Web accessibility. The WAI develops guidelines for Web accessibility; support materials to help understand and implement Web accessibility; and Web accessibility resources.

Guidelines on accessible web design

Web Content Accessibility Guidelines

In 1999 the WAI published the Web Content Accessibility Guidelines WCAG 1.0. These are generally accepted as the definitive guidelines on how to create accessible websites.

Since 2003, the WAI has been working the second edition of these guidelines, the WCAG 2.0. This is currently at the Working Draft stage.

Other guidelines

United Kingdom

In the UK, the Disability Rights Commission (DRC) in collaboration with BSI have published Pas 78 which outlines good practice in commissioning accessible websites.

Legally required Web accessibility

A growing number of countries around the world have introduced legislation which either directly addresses the need for websites and other forms of communication to be accessible to people with disabilities, or which addresses the more general requirement for people with disabilities not to be discriminated against.

USA

In the US, the Section 508 of the Rehabilitation Act requires that Federal agencies and their contractors give disabled employees and members of the public access to information (including web sites) that is comparable to the access available to others; the Americans with Disabilities Act of 1990 prohibits discrimination on the basis of disability; and Section 225 of the Telecommunications Act of 1996 requires suppliers to make telecommunications products and services accessible unless not requiring sigificant difficulty or expense. It is complicated, and dependent on case law, exactly how the latter two apply to Web site accessibility.

Australia

In Australia, the Disability Discrimination Act 1992 was used successfully by a blind man in 2000 who took SOCOG, the Sydney Organising Committee of the Olympic Games, to court because they had failed to ensure that the official website of the Sydney Olympic Games was adequately accessible to blind users.

United Kingdom

In the UK, the Disability Discrimination Act 1995 (DDA) does not refer explicitly to website accessibility, but makes it illegal to discrimate against people with disabilities. The DDA applies to anyone providing a service; public, private and voluntary sectors. The [Code of Practice: Rights of Access - Goods, Facilities, Services and Premises] document published by the government's Disability Rights Commission to accompany the Act does refer explicitly to websites as one of the "services to the public" which should be considered covered by the Act.

Website accessibility audits

A growing number of organisations, companies and consultants offer website accessibility audits. These audits, a type of system testing, identify accessibility problems that exist within a website, and provide advice and guidance on the steps that need to be taken to correct these problems.

A range of methods are used to audit websites for accessibility:

Automated tools are available which can identify some of the problems that are present.
Expert technical reviewers, knowledgeable in web design technologies and accessibility, can review a representative selection of pages and provide detailed feedback and advice based on their findings.
User testing, usually overseen by technical experts, involves setting tasks for ordinary users to carry out on the website, and reviewing the problems these users encounter as they try to carry out the tasks.

Each of these methods has its strengths and weaknesses:

Automated tools can process many pages in a relatively short length of time, but can only identify some of the accessibility problems that might be present in the website.
Technical expert review will identify many of the problems that exist, but the process is time consuming, and many websites are too large to make it possible for a person to review every page.
User testing combines elements of usability and accessibility testing, and is valuable for identifying problems that might otherwise be overlooked, but needs to be used knowledgeably to avoid the risk of basing design decisions on one user's preferences.

Ideally, a combination of methods should be used to assess the accessibility of a website.

References

External links

Standards and guidelines

The main page for the [W3C's] [Web Accessibility Initiative (WAI)]
The [W3C's] WAI [Web Content Accessibility Guidelines 1.0]
[Wikipedia accessibility guidelines]
[Illinois HTML/xhtml Accessibility Best Practices]
[New York State Mandatory Technology Standards for Accessibility of State Agency Web-Based Intranet and Internet Information and Applications] – Fourteen standards derived from both U.S. Section 508 and the WAI's WCAG 1.0 and required for NYS agency web sites.
[Americans with Disabilities Act Section 508 Guidelines] and [Section 508 Homepage]

Government regulations

[Disability Discrimination Act UK]
[Section 508] - requires U.S. government web sites to be accessible
[New York State Technology Policy P04-002] – Requires Accessibility of State Agency Web-Based Intranet and Internet Information and Applications, requires all State entity web sites to be accessible according to NYS standards which are a hybrid of Section 508 and the W3C's WCAG 1.0. Updates Statewide Technology Policy 99-3, which required sites to conform to the W3C WCAG 1.0, Priority one checkpoints only.

Resources for users

Articles

[Web Accessibility Explained] - Indepth overview of web accessibility, development and legal standards.

Resources for designers

[WebAIM: Web Accessibility Tutorials and Information]
[RNIB Web Access Centre]
[Accessibility Advice] from The National Library for the Blind (NLB), which includes links to their [Visionary Design Awards]
[Illinois Center for Instructional Technology Accessibility]
[National Disability Authority (Ireland) - ICT Accessibility]
[NYS Forum IT Accessibility Committee] – Provides support services for NYS government via training and resources to assist web developers in understanding and implementing NYS's policy and standards. Committee also sponsors a [resource web site].
[Guild of Accessible Web Designers]
[Accessites.org] – Accessible Webdesign Awards
[Knowbility] - Non-profit organization that provides accessibility assessments and training
[EServer TC Library: Web Accessibility]
[Accessible Net]
[Interno Tredici]
[Web Design Reference] - A huge mega-reference (over 3,000 links) of information and articles dedicated web design and development. The site advocates accessibility, web standards, usability and many related topics. It features a listserv and RSS feed for site updates.
[Building Accessible Websites book serialization]