Guidelines
A number of guidelines exist which should be used when creating or redeveloping websites. Some of the guidelines can be a little confusing at first, but there are lots of resources and tutorials to help you understand them.
There are a variety of guidelines and standards available around the world with many individual countries developing their own. While many of them offer similar information, it pays to have a look at a few as some offer issues not covered elsewhere.
The most commonly referred to international guidelines are the Web Content Accessibility Guidelines (WCAG1.0). There are 14 high-level accessibility guidelines which are broken down into 65 specific checkpoints.
Each checkpoint is assigned a priority level (Priority 1, 2 and 3).
A Web document or resource must satisfy Priority 1 (P1) checkpoints otherwise, according to WCAG1.0 one or more groups (of disabled people) will find it impossible to access information in the document.
If Priority 2 (P2) checkpoints are not satisfied, one or more groups of disabled people will find it difficult to access information in the document.
If Priority 3 (P3) checkpoints are not satisfied, one or more groups of disabled people will find it somewhat difficult to access information.
If a website passes all P1 checkpoints, it is Level A conformant; if it passes all P1 and P2 checkpoints, it is Level AA conformant; and finally if it passes all P1, P2 and P3 checkpoints, it is Level AAA conformant.
WCAG2.0 is the next iteration of the guidelines and is currently in its final draft. The current draft version is organized into four accessibility principles:
- Content must be perceivable
- Interface components in the content must be operable
- Content and controls must be understandable
- Content should be robust enough to work with current and future user agents (including assistive technologies)
Each principle includes a list of guidelines addressing the principles. Success criteria are included to assist in testing conformance to the guidelines. The success criteria are organized into three levels.
Level 1 success criteria must be reached to achieve a minimum level of accessibility.
Meeting Level 2 success criteria will result in the website, document or resource achieving an enhanced level of accessibility.
Level 3 will achieve additional accessibility enhancements.
Levels 1 and 2 can reasonably be applied to all Web content, whereas Level 3 may not necessarily be applied to all Web content. As with WCAG1.0 conformance statements involve Level A, AA and AAA.
A comprehensive set of guidelines that covers both usability and accessibility is the Research-based Web Design and Usability Guidelines developed by the US Department of Health and Human Services (HHS Guidelines).
