The Web Content Accessibility Guidelines (WCAG 2.0) is a W3C defined guideline that gives web developers to develop accessibility compliant web applications. As per the WCAG documentation the web content here would refer to the following information that is available on the internet:
- Natural information such as text, images, and sounds
- Code or markup that defines structure, presentation, etc.
The WCAG has 12 guidelines that are organized under the following four principles. If any web site does not meet any of the following principles then it cannot be used by disabled audience members. For each guideline a “Success Criteria” has been defined. The web content must be testable under the success criteria and be a pass to be acceptable as compliant to the respective guideline.
Perceivable: The information that is available on the webpage must be perceivable (i.e. to become aware ). The information cannot be hidden from all of the senses. For example if a blind user cannot see the text, the web page must be compliant for a voice reader to be able to perform an audio voice over. The guidelines under this principle are:
- Guideline 1.1 – Text Alternatives.
- Guideline 1.2 – Time based media.
- Guideline 1.3 – Adaptable.
- Guideline 1.4 – Distinguishable.
Operable: The user must be able to operate the application and it cannot require a interaction that the user cannot perform at all. For example if a user is not able to use a mouse then he/she must be able to use a keyboard instead. The guidelines under this principle are:
- Guideline 2.1 – Keyboard Accessible.
- Guideline 2.2 -Enough Time.
- Guideline 2.3 -Seizures.
- Guideline 2.4 – Navigable.
Understandable : The user must be able to understand the information that is presented in the website and also understand how to interact with the website. The guidelines under this principle are:
Robust : The application must be robust enough to be well interpreted by assistive technologies. The guideline under this principle is:
The Web Content Accessibility Guidelines 2.0 are organized into three levels of conformance:
- Level A – The most basic web accessibility features. They don’t focus on one type of disability only. They will also have the lowest impact on the presentation logic and business logic of the site. Finally, implementation of these requirements will typically be the easiest.
- Level AA – This success criteria deals with the biggest and most common barriers for disabled users and have a high impact for users. Sometimes only specific user populations will be impacted, but the impact is important.
- Level AAA – The highest (and most complex) level of web accessibility.
Texas Administrative Code 206 requires all web content to meet A/AA criteria.