Accessibility and Universal Design
What this domain tests
Domain 2 tests the difference between accessibility, usability, and universal design, the seven Principles of Universal Design, and WCAG’s POUR structure.
Core rules
- Accessibility: people with disabilities can perceive, understand, navigate, interact, and contribute.
- Usability: effectiveness, efficiency, satisfaction for intended users; accessibility is a prerequisite.
- Universal Design (UD): design usable by all people, to the greatest extent possible, without adaptation. Ron Mace’s seven principles: equitable use; flexibility in use; simple and intuitive use; perceptible information; tolerance for error; low physical effort; size and space for approach and use.
- Inclusive design emphasizes designing with excluded groups; accessible design often targets specific disability accommodations.
- WCAG POUR: Perceivable, Operable, Understandable, Robust. Each success criterion is testable and technology-agnostic; A is minimum, AA the common legal/policy target, AAA enhanced.
- Reasonable accommodation is individual retrofit; universal design is proactive and benefits everyone.
Worked example
A team designs a registration form. Labels are programmatically associated with inputs; errors are described in text and linked to the field; all controls are keyboard operable with visible focus; text contrast is at least 4.5:1. Reasoning: labels satisfy Perceivable/Understandable; keyboard operation satisfies Operable; semantic HTML supports Robust. The form is not “universally designed” merely because it has a large font - flexibility and error tolerance matter.
Traps
Treating UD as one-size-fits-all; claiming WCAG AAA is the usual legal standard; checking only automated tools; confusing contrast thresholds (4.5:1 normal text, 3:1 large text and UI components); adding ARIA instead of using native semantics.