What is Website Accessibility?
People access websites in all sorts of different ways - without sound, without a mouse, without sight (using a screenreader), with images turned off, even in a plain-text Lynx-style browser, or on a web-enabled mobile phone or PDA.
When we design websites for people with perfect sight, screen displays of at least 800x600 resolution, and assuming use of a mouse, we cut out a large number of potential visitors - more than you might think!
If your website relies on Javascript, or Flash, without providing alternatives, it won't be accessible to a large number of web users. You should use these technologies to provide enhancements to your website, and not as the basis thereof. For example, if your website navigation is entirely Javascript-based, not only will some of your visitors not be able to navigate your site, but the search engines certainly won't be able to!
To ensure that your website is accessible to everyone, bear some of the following points in mind:
1. Use ALT tags for your images, to explain what the image is - particularly if the image primarily contains text. But if the image is a spacer image (i.e. has no contextual value), leave the ALT text blank.
2. Don't use client-side image maps. If you have to, provide a text equivalent.
3. Add titles to links. Didn't you know about the "title" attribute for all your "a href" anchor tags? It's there for a reason - screenreaders will read it, many browsers will display it in the status bar or as a tooltip. This is especially useful where the link text might not give the visitor enough reason to click on the link. You can use the title attribute to "flesh out" your link, particularly in navigation / menu bars where your links are short (e.g. one word).
4. Try not to open new windows.
These are the absolute, bare basics for creating an accessible design. If you are really keen on making your website totally accessible, then browse around Dive Into Accessibility. Be warned - it's addictive!