An Introduction to Web Accessibility

9 March 2006

1. About Web Accessibility

Web accessibility is the provision of online resources and services which do not exclude people on the basis of their disability or impairment. Web accessibility takes account of a range of users including people who are blind or visually impaired, the deaf community, physically disabled people, users with dyslexia and learning disabled people.

2. How Disabled People Access the Internet

Disabled people access the internet in a multitude of ways. Some may make use of 'assistive technologies' – devices which enable them to access web content and services.

Assistive technologies include:

  1. Screen and Braille Readers: Software used by blind and visually impaired people which reads out website content and enables them to navigate, fill out online forms etc. Examples of screen readers include JAWS (Jobs Access With Speech), Window Eyes and IBM's 'voice reader' Home Page Reader. Some people may also use a braille reader, which presents web content on a refreshable braille display.
  2. Screen magnification software and hardware: Used by visually impaired people to magnify web content for increased legibility.
  3. Text-only browsers: Used by visually impaired people to access web content without graphics and multimedia (e.g. Lynx ).
  4. Keyboard only users: Physically disabled people may be unable to use a mouse, instead accessing the web using a keyboard or keypad.
  5. Adapted standard browsers: Other people may have adapted a standard browser (e.g. Internet Explorer) for their own needs, for example by enlarging the size of the text, using a personalised style sheet or turning off images or technologies such as javascript.

3. Web Accessibility in Practice

Accessible web design takes account of the range of devices which disabled people may use to access the internet. This is done by providing web content and navigation which is device independent, i.e. the navigation, content and functionality of the website is available irrespective of whether the visitor is using a screen reader, braille reader or standard browser.

4. Other Benefits

An accessible website will provide added benefits for the site owner:

  1. Accessibility Equals Usability: An accessible website will also be a more usable website. It will provide a more effective, efficient and satisfying experience for all visitors.
  2. Improved Search Engine Rankings: An accessible website will be more visible to search engines such as Google and thus improve the site's search engine rankings.
  3. Easier updating: Websites which are standards compliant and accessible effectively separate structure from content. As a result, updating the site becomes simpler and more cost effective.
  4. Short download times: Accessibility enhancements will in most cases, reduce the the file size of the page and improve download times, resulting in an improved user experience. For companies who pay for bandwidth this may have the added benefit of reduced costs.
  5. Visitors on the move: Websites which are accessible to screen readers are also more likely to be accessible via other devices, such as Personal Digital Assistants and Web-enabled phones.

5. Accessibility Standards

The most widely adopted set of standards for web accessibility are the Web Content Accessibility Guidelines 1.0 (WCAG). They provide specifications regarding the construction of websites in order to ensure access for people with disabilities. They are also used as a baseline for testing the accessibility of websites.

The guidelines have been adopted by Australia, Canada, Japan and the European Union e-Europe Initiative (for public sector web sites).

The WCAG guidelines are divided into 3 Priorities, Priority 1 (A) being the most basic level of compliance. Most countries which have used the WCAG guidelines as the benchmark against which web accessibility is to be measured have specified Priority 2 (AA) as the minimum level of compliance.

6. Legal Requirements

The Disability Discrimination Act (DDA), 1995 made it illegal for providers of goods, facilities and services to discriminate against the 9 million disabled people in the UK by less favourable treatment . The Act applies to private companies and public bodies who provide a service to the public, and states that service providers should make reasonable adjustments to their services so that disabled people can access them.

Under the Act, websites are considered to be the provision of a service and are therefore covered by the legislation.

To date, the DDA's applicability to the web remains untested in law since there have been no legal challenges.