Table of Contents
Web Accessibility
These materials are designed to provide an introduction to Web accessibility issues and tools, and will discuss how to apply accessibility concepts to Web pages you design at the University of Virginia and elsewhere.
A review of this site will prepare you to:
- Describe why implementing Web accessibility standards is part of good Web page design;
- Evaluate accessibility scenarios and review Web design elements appropriate for the most common disabilities;
- Apply simple tools to simulate visually impaired access to sample Web sites;
- Test Web sites for accessibility using reference materials and validation tools.
What Is Web Accessibility?
"Web accessibility involves the ability of a web page to be read and understood [by anyone], using adaptive technologies where necessary."Leo Valdes
Accessibility on the Internet
Why Web Accessibility?
The following points explain why accessibility is an important consideration when designing Web pages. Accessible pages:
- Allow for larger audience participation.
- Improve usability for all.
- Permit device independence.
- Improve efficiency.
- Promote HTML standards that can be supported by all browsers.
- Improve search engine listings.
- Demonstrate social responsibility.
Who Needs Web Accessibility?
The following three groups of people benefit from accessible Web sites:
- Disabled persons:
- Visually impaired;
- Hearing impaired;
- Learning impaired;
- Physically challenged.
- Users of wireless handheld devices:
- Personal digital assistantants (PDAs);
- Digital Web-enabled telephones.
- Persons on low-bandwidth internet connections:
- Dialup users at home;
- International users with slow or expensive connections.
Barriers to Web Accessibility
The following five Web design techniques create barriers to Web accessibility, and should be avoided:
- Pages using frames:
Frames cause many complex problems, including inhibiting accessibility. For a detailed explanation of common issues with frames, see the page on frame problems. - Non-descriptive graphics:
Graphics which are not critical to the content being explained should be left out. In addition, graphics which contain information not included in a text explanation attached to the graphic or included elsewhere in the site should be avoided. - Video or audio content without captioning;
Creating video and audio Web content which is accessible to hearing, visually, cognitively, or bandwidth impaired users takes time, effort, and expertise. Designing sites which use less complex devices may be a better use of your design time. - Overly complex screen layouts:
If you cannot make sense of your site when viewing it in a text-only reader, simplify your layout so that content appears linearly and logically when read as it appears in the source or text view. - Pages that cannot be read with assistive technologies:
Using Flash for navigation, or PDF files with critical content, means your site may not be readable with the special software designed to assist users with disabilities. If you cannot redesign your site to be accessible, you will need to create alternate pages that contain the same information in a simpler, accessible design. Two sets of pages means you must stay on top of updates to both sites when making changes.