WCAG Layers of Guidance


Four Principles of WCAG


The WCAG consists of four principles that form the acronym POUR. For a quick overview of the WCAG principles, see WCAG at a Glance.

Perceivable


How does your audience perceive the digital content you create and share? Should they be able to see it? Hear it? Both? What if they have vision and/or hearing loss? Are there alternative modes of representation?

There are four guidelines and 20 A and AA success criteria for Perceivable.

Operable


How does your audience operate within your digital content? Does it depend entirely on using a mouse? What if they don’t use a mouse? Can they use a keyboard instead? What about a touch screen, or voice commands?

There are five guidelines and 17 A and AA success criteria for Operable.

Understandable


Is your content understandable to your whole audience? Is it readable? What if their first language is not the primary language of the instructions? Are there guides for understanding acronyms, abbreviations, jargon? Is everything arranged consistently and predictably?

There are three guidelines and 10 A and AA success criteria for Understandable.

Robust


Is the platform and content created in a way that works for everyone, including people who use assistive and mobile technologies?

There is one guideline and 3 A and AA success criteria for Robust.


Success Criteria


Each of the four WCAG principles has its own set of guidelines and Success Criteria (SC). Each SC also includes a list of technology-specific techniques for meeting it.

In total, there are 78 Success Criteria in the WCAG 2.1 standard, categorized by three levels of conformance: A, AA and AAA.

Rice Policy 851 does not require us to meet AAA success criteria.

There are only 50 A and AA criteria, 30% to 40% of which are relevant to most content authors at Rice. There are A and AA SC that apply only to site admins, developers, and technology vendors who provide products and tools.

3 Levels of Conformance

LEVEL A, success criteria we MUST meet.
Level A criteria form the baseline for digital accessibility. The techniques associated with level A show us how to avoid designing barriers into our digital information and help us comply with nondiscrimination laws.

LEVEL AA, success criteria we SHOULD meet.
Level AA criteria go beyond baseline requirements and help improve the quality of our digital information without requiring significantly more effort. Rice University asks us to meet level AA criteria whenever relevant to the digital information we create and share.

LEVEL AAA, criteria What you COULD do.
Level AAA criteria go even further and empower our audience with greater choice. Rice University does not require that Level AAA criteria are met, but it is recommended whenever possible.


Techniques


There are dozens of individual techniques in WCAG 2.1, but it is important to note that none of them is required. Each technique is a technology-specific recommendation for ensuring that a success criteria (SC) is met. Meeting SC is required. Each SC can have multiple techniques depending on the context and technology.

Learn more about WCAG techniques.

Basics Technique Guides


We distilled the WCAG 2.1 success criteria and techniques with the highest impact for content authors into the following topical guides.

Guide on Forms coming soon.