"The power of the Web is in its universality.
Access by everyone regardless of disability is an essential aspect."
-- Tim Berners-Lee, W3C Director and inventor of the World Wide Web
Accessibility most affects users with low vision, no vision, color blindness, and in some cases hearing impairment.
Depending on your goals, accessibility considerations should also include older computer systems and browser formats.
Following are some basic guidelines.
For a complete checklist, visit: W3C's site for Accessibility Guidelines
- Provide content that, when presented to the user, conveys essentially the same function or purpose as auditory or visual content.
- Ensure that text and graphics are understandable when viewed without color.
- Mark up documents with the proper structural elements.
Control presentation with style sheets rather than with presentation elements and attributes.
- Use markup that facilitates pronunciation or interpretation of abbreviated or foreign text.
- Ensure that tables have necessary markup to be transformed by accessible browsers and other user agents.
- Ensure that pages are accessible even when newer technologies are not supported or are turned off.
- Ensure that moving, blinking, scrolling, or auto-updating objects or pages may be paused or stopped.
- Ensure that the user interface follows principles of accessible design: device-independent access to functionality, keyboard operability, self-voicing, etc.
- Use features that enable activation of page elements via a variety of input devices.
- Use interim accessibility solutions so that assistive technologies and older browsers will operate correctly.
- Use W3C technologies (according to specification) and follow accessibility guidelines.
Where it is not possible to use a W3C technology, or doing so results in material that does not transform gracefully, provide an alternative version of the content that is accessible.
- Provide context and orientation information to help users understand complex pages or elements.
- Provide clear and consistent navigation mechanisms -- orientation information, navigation bars, a site map, etc. -- to increase the likelihood that a person will find what they are looking for at a site.
- Ensure that documents are clear and simple so they may be more easily understood.