Accessibility in web provides a huge degree of usability

Accessibility in web design provides a high degree of usability for people with disabilities. Mostly based on general design principles, with some specific extra facilities, accessible design ensures that you do not deliver a restricted or exclusionary message and therefore image. Full accessibility design guidelines are provided by the W3C, the standards body for the Web. While the focus of this section is largely on design for blind users who access the web page via a screen-reader, if you make pages accessible in the ways suggested you will improve clarity for all users. The BBC has developed a script called Betsie, which will convert pages to plain HTML.

The development of this service is the subject of a case study provided by Betsie’s developer, Wayne Myers, on page 107. There can be a fine line between enabling and excluding technology. All it takes is some careless HTML, the addition of a few unsupported images and some multimedia frills, and entire web sites can disappear from view for substantial numbers of users. Complying with HTML standards, designing for universal access and applying plain English guidelines should be the foundation of any well-designed, content-driven web site, and not just a philanthropic afterthought.

The Disability Discrimination Act 1995 includes requirements for providers of information services which of course includes web sites to enable these services for unimpeded access by disabled users. Making your site accessible is not just good practice, or a way of maximising customer service, it is a legal requirement, albeit one that is little enforced as yet.

The HTML design suggestions below are drawn from a variety of sources. Their implementation need not add significantly to the design or management costs of a web site even less so if they are designed in from the outset. Each adds a little to the universality of the medium. Combined, they can ensure that no users are excluded for reasons of design. The focus is largely on design for blind users who access web pages via a screen-reader. Blind or visually-impaired users are of course not the only people who have difficulty accessing Internet-based information, but the difficulties that this population group experience are probably those most readily resolved by web design. Access solutions for those with learning difficulties and physical mobility problems are mostly centred on support and training, or on hardware and software development, rather than on design of the content.

The suggestions below are based on three basic web design principles: pages should not be browser-specific; they should make sense to all their readers, not just those using particular technologies; images (their description or their meaning within the page) should be accessible to all readers, even those who cannot see them. Universal access to information is a right, not a favour, and designing accordingly is entirely compatible with exciting and attractive web page design.

Technological Solutions

Screen-readers combined with a voice synthesiser (or Braille output), typically using the Lynx text browser, provide access to those with sight or mobility problems. Some screen readers can work with graphical browsers, but most design advice here and elsewhere is based on the assumption that they are ‘reading’ Lynx. All graphical browsers provide some customisation facilities, notably the ability to adjust colour, type size and font. Dyslexic or partially sighted users can thus compensate for some poor or problematic designs. Screen magnifiers provide further control over size (and often colour too). Opera (http://www.opera.no) provides a full set of keyboard commands to replace the use of a mouse, as well as a zoom facility to enlarge the screen content up to 1,000 per cent or reduce it to 20 per cent. PwWebSpeak from is Sound (http://www.prodworks.com) converts text to speech, supports variable text sizes and allows words in a particular paragraph to be listed and spelled out. It can also provide response to voice commands. A list of enabling technology as well as accessibility design guidelines can be found on the RNIB web site (http://www.rnib.org.uk).

Hypertext in Context

Using ‘click here’ as a hypertext link is browser specific Lynx users simply don’t click at all and those who control browsers with keyboard commands instead of a mouse are likewise excluded or confused. It is also poor design, as web pages may be printed out, which will render this instruction redundant.