Web Page Accessibility

December 29, 2008 by D. A. Shaver

What is Web Accessibility?

Web page accessibility is making the web site usable by people with disabilities. A common theme throughout might be; simplicity is best for getting your web site seen by both search engines and persons with disabilities.

Alt text

Alt text is the text that appears when you hold your mouse over an image; it is one of the most important aspects of an accessible web site.

Link Text

Persons with disabilities such as blindness will often navigate a page using special software and jump from link to link using the tab key. This demonstrates the importance of link text, which is also important for getting your web site indexed by search engines. Good link text describes where the link goes, for example in the sentence “You can buy a book” the link text should be “buy a book” not “You”. With this in mind it is easy to understand why you should never use “click here”.

Navigation

Text links are best because they will always work with the text only software used by persons with disabilities. This is also what is wrong with pictures containing text since the pictures cannot be seen. JavaScript navigation is another example since it cannot be seen by software used by persons with disabilities. Every one of these three examples also applies to search engines, if you use this kind of navigation search engines and persons with disabilities will not be able use your web site. If these types of navigation are used you should provide text alternates. By denying access to these groups your web site will not be indexed by search engines and persons with disabilities will not be your customers.

Ban Splash Screens

Splash Screens are front pages that frequently have only a picture that usually reads, “Enter”. These are extremely user hostile in many ways because text is usually absent, leaving a text browser no way to enter or view the web site. All navigation should have text only alternatives. People, especially persons with motor skill deficiencies, should never be asked to click again just to get to the content, it should be on the front page.

Valid Mark-Up

Use CSS instead of tables as much possible and never use nested tables. Tables should only used for columns of data not web page layout. It is important to use alt tags for images, image map links and graphical buttons. These should accurately describe the image and should be as short as possible. Long alt tags will not fit into a graphical reader for blind persons. Use current proper document types. Validate your mark up at http://validator.w3.org/

Lynx Browser

The lynx browser is a text only browser originally developed in 1992 at the university of Kansas. Nowadays its usefulness is primarily to see how a web site appears to search engines and persons with disabilities. There is lynx browser anyone can use to test their web site at http://www.delorie.com/web/lynxview.html