WCAG 2.0 Overview
WCAG 2.0 is divided into four principles. Each principle is divided into guidelines, and guidelines are divided into success criteria. All success criteria is marked by a certain level of conformance.
The four principles are the following:
It is not essential to remember the principles, their only purpose is to order the many guidelines into a logical order.
Altogether, there are 12 guidelines under the four principles. The guidelines, are also there to further divide the success criteria into a logical order. When you work with your web site, most likely you will have to consider success criteria under most guidelines, as they cover different areas of web accessibility. It is likely that while some of the success criteria will be applicable to your site under most guidelines, still, many of the success criteria will not apply.
This is where things get interesting. The guidelines are divided into success criteria. When you evaluate your web site for accessibility, or would like to plan an accessibility strategy, you will go through these success criteria, and make sure that these are met, as the WCAG technical language calls it, they are conformant with WCAG.
Three Levels of Conformance
Each success criterion is indicated by a level of conformance, which could be Level A, Level AA and Level AAA. When you create an accessibility strategy for your web site, determine which level you would like to conform with. The levels are as follows:
Level A: when you conform with Level A, it means that you eliminate the major accessibility barriers. This does not mean that your web site is very accessible, it only ensures that it is accessible for the most part for most scenarios. Unless you have a specific reason to use only Level A, it is not recommended.
Level AA: this conformance level ensures a very good level of accessibility. If you conform with Level AA, it means that your web site will be accessible for most people, under most circumstances, with most technologies they use. Level AA is what most accessible sites follow, and when WCAG conformance is required, Level AA is mostly specified.
Level AAA: this conformance level is very meticulous, ensures a very high level of accessibility, but it is also very difficult to maintain. Level AAA is relevant in very specific situations, mostly related to live material, or just to refine the requirements of Level AA. It is not to say that Level AAA is impossible to conform with, but in many instances you will not have content that most of it applies to. When it comes to live presentations, conforming with Level AAA could mean a certain financial requirement as well, and very often when a small organization is not able to provide this financial obligation, an alternative solution is acceptable, which conforms with Level AA.
Please note that regardless of all efforts, it is not possible to create a site which is accessible to all people on all levels. In theory, to achieve such a site, you will have to consider any number of disabilities imaginable, any number of languages, and any levels of education, plus the combination of all of the above. The purpose is not to create a site which is absolutely bulletproof, rather, to create a site which has all intentions to make it accessible in the most possible situations within reason, for which the WCAG is a very reasonable measure.
In this tutorial, we will examine all three levels with equal importance, as your organization will have to make the decision on the level of conformance.