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Information underload - Web design and people with disabilities

Julie Howell, Royal National Institute for the Blind, UK

Can everyone read your Web site?

The growth of the World Wide Web has meant that many people with serious sight problems are now able to enjoy a wealth of information that was previously unavailable to them, from news and reviews to timetables and online shopping. With the help of synthesised speech and braille display technology, even completely blind people can use the Internet.

But for these technologies to work properly, Web pages must be written in correct HTML (hypertext mark-up language). Many sites are unusable by blind people simply because they are not written in correct HTML (or not written in HTML at all). People with disabilities have a moral right to be able to use all Web sites, but many designers still fail to recognise this.

Most people with sight problems have some useful vision, and read online text in exactly the same way as fully sighted people: with their eyes. However, the needs of people with poor sight vary considerably, depending on how their eye condition affects their vision. Some people require large text, while others can only read smaller letters. Most people need a highly contrasting colour scheme, while some can only read yellow text on a black background. To cater for everyone, Web sites should be flexible in design, enabling the individual to adjust the text and colour settings to suit their needs and circumstances.

In contrast, people with very little or no vision, read Web pages with the help of access technology installed on their computer. Synthesised speech software reads the content of Web pages aloud through a speaker, while braille software outputs to a retractable display, so that the Web site can be read by touch. Careful design is paramount for people accessing the Web in these ways, as inappropriate use of HTML can render a site unreadable.

And remember: an accessible Web site is one that can be visited by anybody. It is perfectly possible to produce an attractive, dynamic design that remains fully accessible. Web sites that are designed intelligently benefit everyone - not only people with disabilities.

There are 1.7 million people in the UK with serious sight problems or blindness. Can they use your site?

10 tips on providing open access to your Web site
  1. Is the text legible? Contrast is the most important factor to consider when designing sites that everyone can use. Go for text and background colour combinations that offer maximum contrast (such as a pale pastel shade for the background and a dark, bold colour for the text).
  2. Is the design flexible? Is it easy to change the colours and the size of the text by adjusting browser settings? Sites with inflexible designs may be difficult for people with colour blindness to read, while resizable text makes a site accessible to people with visual impairments.
  3. Does every image have 'alt-text'? The alternative text attribute of the image tag exists to provide a description of the image for people accessing the site via speech synthesis software. If you wish to provide a detailed description, use the LONGDESC attribute. If the image is little more than eye-candy, the alt-text may be set to read '*'. Better still, take the opportunity to provide some extra information that only blind people and search engines will read.
  4. Is there a site map? A site map will help visitors to get an impression of the layout of the site quickly, and will make it easier to navigate. Remember, sighted people become lost on large sites too, so it's not only your disabled visitors who will benefit.
  5. Do links make sense out of context? Sighted people scan screens of information very quickly to locate the parts that interest them. If you cannot see, and rely on synthesised speech technology to 'hear' Web sites, you need another way to get a quick impression of the content of a page. Commonly, the access software blind people use will provide its owner with a list of all the links on a page as a means of getting the 'flavour' of the overall content. If a link contains only the words 'click here', its function will not be obvious if it is presented out of context. All links should contain enough useful information about their destination that they make sense on their own, without surrounding text or graphics. Again, this is not an optional 'extra' for sight-impaired people - clear navigation benefits everyone.
  6. Are imagemaps accompanied by text links? Some of the software packages that blind people use to access the Web cannot read imagemaps, so it is important to make text links available as well. As a rule, simple text-based designs are more universally accessible, no matter what technology is being used to access them.
  7. Do frames have titles, or is 'noframes' used? Some blind people may be using software that cannot read frames. It is vital that the NOFRAMES tag is used to offer these people alternative frames-free versions of your pages. And remember, using NOFRAMES to suggest that the reader downloads a graphical browser may not be too helpful! Where frames are used, ensure that they are titled, or the blind visitor may only hear 'link to a frame' without any indication of its content.
  8. Are alternatives offered for JavaScript, applets, Flash or plug-ins? If you are writing pages in anything other than HTML, you may be excluding some people from your site. Not everyone has the ability or capability to download and use all scripts and plug-ins. Always provide plain HTML alternatives so that everyone can read the information on your site.
  9. Is Access Adobe available for PDF files? The Adobe Acrobat Reader is not compatible with the access software many blind people use. The company have now made a product called 'Access Adobe' available for these users. It transforms PDF files into HTML, and can be found on the Adobe website
  10. Do all pages pass the 'Bobby' test? Before launching your site online, perform one final check that there are no major accessibility problems. The Centre for Applied Special Technology (CAST) has created its own automated accessibility checker, code-named 'Bobby'. Running a site through Bobby will test for HTML 4.0 compatibility, that all graphic elements have text equivalents, and that written summaries have been provided for graphs and statistical material. Users can also check that their site is compatible with non-standard Web browsers, including Lynx, Mosaic, Opera and WebTV. Sites passing the Bobby test receive a kitemark and are eligible for inclusion in CAST's database.

Julie Howell

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