How to be Accessible
How can you be sure your Web site is accessible? A good place to start is to evaluate your site using the Section 508 accessibility standards to which federal agencies must comply. You can use these standards as guidelines for making your Web site accessible to everyone. The guidelines are well supported by vendors, trainers, and software.
Step One: Check Your HTML
Be sure your HTML is error-free and complies with standards developed by the World Wide Web Consortium (W3C). Most assistive technologies used by people with disabilities are based on these standards. Error-free, well-formed, standards-compliant HTML is the foundation of an accessible Web site.
Use the following tools:
- W3C HTML Validator - Is your HTML well-formed and valid?
- Tidy - W3C's nifty HTML cleanup and accessibility evaluation utility.
Step Two: Follow the Guidelines
HTML includes many features you can use to make your Web site accessible. Follow these guidelines on how to use those features. Click on the link at the beginning of each item for an explanation and examples.
Section 508 Guidelines (1194.22 Standards)
(a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content).
(b) Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation.
(c) Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup.
(d) Documents shall be organized so they are readable without requiring an associated style sheet.
(e) Redundant text links shall be provided for each active region of a server-side image map.
(f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
(g) Row and column headers shall be identified for data tables.
(h) Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.
(i) Frames shall be titled with text that facilitates frame identification and navigation.
(j) Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz.
(k) A text-only page, with equivalent information or functionality, shall be provided to make a Web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes.
(l) When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology.
(m) When a Web page requires that an applet, plug-in or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with §1194.21(a) through (l).
(n) When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues.
(o) A method shall be provided that permits users to skip repetitive navigation links.
(p) When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required.
The following tutorials provide clear explanations and plenty of examples.
- Web Accessibility for Section 508 - Jim Thatcher
- Accessible Web Design Tutorials - WebAIM
- Web Accessibility - IBM
Step Three: Evaluate Your Site
Now that you have an idea of the methods of accessible design, check some of your pages with an accessibility evaluation program. Several good ones are available on the Web.
- Cynthia Says - A utility to help you identify and repair significant barriers to access by individuals with disabilities.
- Functional Accessibility Evaluator - University of Illinois at Urbana-Champaign
- WAVE Accessibility Checker - WEBAIM
- Online version of Tidy that also does accessibility evaluations using W3C's criteria.
More
The following resources provide additional information and tools for making your Web site accessible to visitors with disabilities.
Using Web Publishing Software
Accessible Media
-
National Center for
Accessible Media
- MAGpie - Rich media accessibility
- Adobe Acrobat (PDF) Solutions For Accessibility
- Macromedia Flash Accessibility Best Practices
- Microsoft Accessible User Interface Articles - MS Developers' Network
- Synchronized Multimedia Integration Language (SMIL) - W3C
