Accessibility Considerations
This domain tests accessibility as part of usability: can people with disabilities, and people in limiting contexts, perceive, operate and understand the product? Expect items on WCAG structure, common failures, assistive technology and the limits of automated checks.
The standard
WCAG 2.x rests on four principles: Perceivable, Operable, Understandable, Robust (POUR). These are expressed as testable success criteria at levels A, AA and AAA. AA is the usual legal and procurement target referenced by EN 301 549 and Section 508.
Recurring failures
- Keyboard traps, or controls reachable only by mouse, and invisible focus indicators.
- Missing alternative text, captions and transcripts.
- Contrast below 4.5:1 for normal text, and information conveyed by colour alone.
- Text that cannot resize to 200%; fixed orientation; time limits that cannot be extended.
- Unlabelled form fields; errors identified only visually.
Testing it
Automated scanners detect only a minority of issues, so combine them with manual inspection against WCAG and testing with assistive technology such as NVDA, JAWS, VoiceOver, TalkBack, switch access or speech input. Ideally include participants with disabilities in usability tests and provide accessible consent and task materials.
Worked example
A registration form marks invalid fields with a red border only. This breaches use of colour (1.4.1) and error identification (3.3.1). Fix it by adding a text message, an icon and a programmatic association so a screen reader announces the error, then retest with keyboard-only and screen-reader users.
Traps
Reporting "automated scan clean" as conformance; testing only with a mouse; demanding AAA everywhere; forgetting cognitive accessibility, plain language, consistent navigation and error prevention.