Understanding the Structure of WCAG 2.0

January 14, 2015 |

Since the WCAG 2.0 standard was published by the World Wide Web Consortium (W3C) in December 2008, it has since become the de facto guideline for basing global Web accessibility standards. This is for good reason – WCAG 2.0 substantially improves the end-user experience for people with disabilities. Instead of providing a minimal level of accessibility, WCAG 2.0’s goals were to level the differences between users with and without disabilities as much as possible. The structure of WCAG 2.0 is based on ensuring that four principles are met – content should be perceivable, operable, understandable and robust for all users regardless of disability.

While WCAG 2.0 can appear daunting at first, it can be best explained as a hierarchy comprising of four levels of information.

  1. Principles. At the highest level, there are four overarching principles that organize WCAG 2.0. These are the principles that Web content should be perceivable, operable, understandable, and robust. For our purposes, these four principles should be seen as providing too high a level of generality.
  2. Guidelines. Each of the four principles has one or more guidelines associated with them. In total, there are 12 guidelines, each providing a slightly higher level of specificity than their associated principle. For instance, guideline 2.1 requires keyboard access to all functionality. While useful, the guidelines are still quite general and may not provide sufficient specificity for developers trying to meet WCAG 2.0. Instead, the guidelines are best seen as an organizational tool for their associated success criteria.
  3. Success Criteria. Each of the 12 guidelines has one or more associated “success criteria,” which provide specific expected behavior and functionality from UI elements. In addition, each success criteria has a level of conformance (level A, AA, or AAA). There are a total of 61 success criteria. Focusing at the success criteria level will likely give developers the highest level of return for their efforts.
  4. Techniques. Each of these success criteria identifies one or more techniques that are required in order to meet or exceed the requirements of the success criteria. WCAG 2.0 provides a plethora of techniques, which are divided into sufficient techniques (generally required to meet a success criteria) and advisory techniques (which further augment meeting a success criteria and which can be considered a best practice). Focusing at the technique level can be a daunting task because each technique can be associated with several different success criteria. Additionally, the techniques are organized by technology and the numbering schema is different from the structure used for organizing principles, guidelines, and success criteria. (A summary of the WCAG 2.0 techniques in available at http://www.w3.org/TR/WCAG20-TECHS/).

To learn more about the benefits of conforming to WCAG 2.0, the global government trend of moving to WCAG 2.0 and information on other accessibility standards like Section 508, download our whitepaper The Global Move to WCAG 2.0 and The Case for Conformance.

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Ken Nakata

Ken Nakata, JD, CIPP/US is the one of the most well-known attorneys in the area of IT accessibility and is the Director of Cryptzone’s Accessibility Consulting Practice (ACP). Nakata’s work focuses on Web and software accessibility from both a legal and technical perspective. Nakata’s ACP team helps organizations manage the change towards accessibility in all aspects, providing consulting services aimed at shaping their accessibility policies and practices, and evaluating the overall state of their Web properties leveraging Cryptzone’s accessibility solutions. He is also a board member for the International Association of Accessibility Professionals (IAAP),of which Cryptzone is a founding member.

Nakata worked for twelve years as a Senior Trial Attorney with the U.S. Department of Justice. He has argued on behalf of the United States government many times before the federal courts and has helped shape the government’s policies for the Americans with Disabilities Act and Section 508 of the Rehabilitation Act. Nakata also worked as Director of Accessibility and Government Compliance at BayFirst Solutions, a Washington, DC consulting firm.

In 2000, Attorney General Janet Reno presented Nakata with the Attorney General’s Award for Excellence in Information Technology. In addition to practicing law, Nakata is active in software and web-based technologies, including Java, JavaScript, SQL, and ColdFusion. In July 2001, he was certified by Sun Microsystems as a programmer for the Java 2 Platform. Nakata is a frequent speaker on both law and technology and is equally adept at conducting one-on-one workshops with programmers and developers as well as explaining law and policy to large audiences. He holds a Bachelors of Art degree in mathematics from John Hopkins University and a Juris Doctor degree from the University of Pennsylvania Law School, and is admitted to the bars of New York, the District of Columbia, Pennsylvania and Washington.

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