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ABOUT WEB ACCESSIBILITY |
| "Web accessibility involves the ability of a web page to be read and understood [by anyone] , using adaptive technologies where necessary." |
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| Leo Valdes |
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| Accessibility on the Internet |
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| http://www.un.org/esa/socdev/enable/disacc00.htm |
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| Background |
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| As the Internet grew and people other than scientists began to access the Web, the limitations of HTML as a presentation medium became irksome. In particular, commercial interest in the Internet resulted in graphic designers making major efforts to bypass the presentational limitations of HTML in the attempt to make pages more attractive and advertising worthy. This process was fueled by the development of graphical browsers and the addition of extensions to HTML for the incorporation of images, tables, and forms. |
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| In spite of many graphical excesses, which often impaired legibility, visual presentation on the Internet improved, probably for the majority of users, but there have been some unfortunate consequences to this procedure of creating Web pages on the exclusive basis of visual impact. The intensely graphical nature of Web pages has created serious problems for users of the Internet who do not or cannot use the latest and greatest graphical browser. |
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| Why Web Accessibility? |
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| These are users who may be using special technology to access the Web because of some physical disability, such as blindness. Such users may be accessing the Web with audio or text browsers or using programs that interpret the graphic screen display using synthesized speech. For this kind of equipment, visual presentation and visual relationships have little or no significance. |
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| The following points explain why accessibility is an important consideration when designing Web pages. Accessible pages: |
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Allow for larger audience participation. |
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Improve usability for all. |
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Permit device independence. |
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Improve efficiency. |
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Promote HTML standards that can be supported by all browsers. |
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Improve search engine listings. |
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Demonstrate social responsibility. |
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| Who needs Web accessibility? |
| The following three groups of people benefit from accessible Web sites : |
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Disabled persons |
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Visually impaired |
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Hearing impaired |
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Learning impaired |
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Physically challenged |
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Users of wireless handheld devices |
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Personal digital assistants (PDA's) |
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Digital Web-enabled telephones |
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Persons on low-bandwidth internet connections |
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Dialup users at home |
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International users with slow or expensive connections |
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| Barriers to Web accessibility |
| The following five Web design techniques create barriers to Web accessibility, and should be avoided |
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Pages using Frames : Frames cause many complex problems, including inhibiting accessibility. For a detailed explanation of common issues with frames, see Desktop Web's page on Frames Problems. |
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Non-descriptive graphics : Graphics that are not critical to the content being explained should be left out. In addition, graphics that contain information not included in a text explanation attached to the graphic or included elsewhere in the site should be avoided. |
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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 that use less complex devices may be a better use of your design time. |
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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. |
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