What is web accessibility?

Web accessibility is about making your web site accessible to the widest possible audience. Because of the lobbying of organisations such as the RNIB, many people associate web accessibility with the visually impaired. However, web accessibility is much broader than that. It is also about providing access for those with motor impairments, learning difficulties and other forms of disability. It is also about making your web site accessible to all, irrespective of what browser technology they are using to access your site or the speed of their Internet connection.

How web accessibility is measured

In practice, web accessibility is primarily (although not exclusively) defined by a checklist set out by the World Wide Web Consortium (W3C). The W3C is a governing body for the web that sets standards for technical development. One set of standards is the Web Content Accessibility Guidelines (WCAG) produced as an output of the W3C's Web Accessibility Initiative (WAI).

The WCAG 2.1 is arranged around four design principles of accessibility; perceivable, understandable, operable and robustness. Each of these principles has twelve guidelines and these have three levels of success criteria, each progressively more demanding. The most basic level of accessibility is success criteria 1 (level A compliance) followed by success criteria 2 and 3 (levels AA and AAA).

Our site

It is our aim that this site achieves WAI level A (or level 1) accessibility compliance. Given the extensive use of maps on this site we propose an approach that complies as far as is reasonably practicable with Level A. In practical terms, some of the key implications of the above approach are as follows.

  • A fundamental characteristic of the accessibility solution will be that any information that is available via a graphically enabled access path (e.g. via clickable map) or presented graphically (e.g. by coloured map or by chart) will also be available in text form (e.g. in data tables). Over the coming months a lot of the text equivalents for inaccessible content will be provided on the site.
  • Descriptive information for any graphical item will need to be available via an alt tag associated with that graphical item.
  • Because many devices do not support javascript the site does not use javascript and will operate gracefully if javascript is disabled in the browser or device.
  • We have removed the flash-based tutorials as most browsers will no longer support them.