What makes a Web site accessible?

* Designing Web sites that can be accessed by all

I've written before about the need for all entities with a Web presence to make sure their Web site is accessible.  In this case, "accessible" means designing the Web site so that it is usable by all people, including those who fall into various classifications:

* People who use assistive technology, such as a screen reader or screen magnifier.

* People with low bandwidth connections or older computer configurations.

* People with disabilities or age-related impairments, such as dexterity limitations or hearing impairments

Still, 95% of all Web sites are inaccessible, according to the Austin organization Knowbility, which promotes barrier-free IT.

Since January, I have been working with Knowbility to promote Web accessibility through a program called AIR-Houston.  AIR stands for Accessibility Internet Rally, and it's a program to match professional Web developers with non-profit organizations that need help developing an accessible Web site.  (Learn more about Knowbility and its AIR programs around the country at http://www.knowbility.org)

As I talk to people about accessible Web sites, I see that everyone agrees they are necessary.  But many people ask me, "What makes a Web site accessible?"  This is one of those questions easier answered by rephrasing it as, "What makes a Web site inaccessible?"  Let's look at a few examples where the design of the site makes it difficult for some people to use.

Most Web sites today are sprinkled with graphics and pictures.  Sometimes those graphic elements are an essential part of the content of the Web site.  While they look nice, a visually impaired individual who is using a screen reader to peruse the Web site can't see these elements.  The screen reader translates text into synthesized speech.  When the screen reader encounters the graphic element, there may be nothing to "read" and the value of this graphic content is lost for that person.  An accessible design technique is to include alt-text that provides a brief but meaningful description of the graphic image.  (If you'd like to see what happens when you use a screen reader to scroll through a Web site, you can sample IBM's Home Page Reader for free at http://www-306.ibm.com/able/solution_offerings/hpr.html)

Tables are often used on Web sites today.  The World Wide Web Consortium, the agency that provides Web accessibility standards, recommends the use of a summary attribute on the table so that the screen reader user can get oriented to the layout and purpose of the table.  Without the summary, a user with a vision impairment may not understand the organization of the information in the table and get confused.

Increasingly, Web sites make use of sounds or video.  A person with a hearing impairment may not be able to hear the sounds.  It's a good practice to include closed-captioning with your video so the user can follow along.  What's more, sounds should not be the only means of communicating with the viewer, but should be accompanied by visual content or cues as well.

What about color?  Well, it looks nice to most of us, but a colorblind user might not think so.  Therefore, color should not be the only method to distinguish screen elements or controls.  For example, if you want to use a green button for "start" and a red button for "stop," then the buttons should be labeled with text as well as color.

Many developers are adding flashy elements to their Web pages to make them more eye-popping.  However, rapid flashes could trigger seizures in individuals with photosensitive epilepsy.  It's better to use subdued graphics or animations with a low flicker rate.

There are many other considerations for making a Web site accessible.  Here are a few good resources for learning more:

* The Access Board, a federal agency committed to accessible design


* Jim Thatcher accessibility consulting


* The Section 508 Web accessibility tutorial


If you want to talk with a consultant about ensuring a fully accessible Web site, I highly recommend Jim Thatcher.  Retired from IBM after a 37-year career, hardly anyone knows more about IT accessibility than Jim.  Not only will he help you create an accessible Web site, Jim will help you create a much more usable one.

If you want to read a good book on accessible Web design, try one of the following:

* "Maximum Accessibility: Making Your Web Site More Usable for Everyone," by Knowbility Director Sharron Rush and John Slatin of the University of Texas (ISBN: 0201774224).

* "Constructing Accessible Web Sites," by Jim Thatcher and other leading experts (ISBN: 1590591488).

Linda Musthaler is vice president of Currid & Company.  You can write to her at mailto:Linda.Musthaler@currid.com

Learn more about this topic

Web Accessibility Initiative of the W3C

Web content accessibility guidelines

Web accessibility for Section 508

WebAIM (Web Accessibility in Mind)

Companies to alter sites to suit blind

Houston Chronicle

States prepping cyberalert plan

Network World, 08/30/04

American ITIL: Best practices win converts

Network World, 08/30/04

Copyright © 2004 IDG Communications, Inc.

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