WCAG 2.0 Release Candidate Part 3 of 5: Level AA
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Part 3 of the look at WCAG 2.0 is going to look at the handful of criteria which make up Level AA. Here then, are the lucky 13.
Level AA: Perceivability
There are 5 success criteria at level AA relating to the perceivability of content.
- 1.2.4 Captions (Live)
- Captions are provided for all live audio content in synchronised media. This is obviously more difficult to achieve than simply for pre-recorded media: you need captioning to be added ‘live’.
- 1.2.5 Audio Description
- Audio description is provided for all video content in synchronised media. Note that the equivalent level A guideline allows either the use of audio description or a full text alternative; as the audio description is likely to provide a better end-user experience for someone than the full text alternative, at level AA this is strengthened to require audio description
- 1.4.3 Contrast (Minimum)
- The visual representation of text and images of text have a contrast ratio of at least 5:1; except for brand logos, incidental or decorative text. Larger scale text (14 point bold or 18 point normal) only requires a contrast ratio of 3:1
- 1.4.4 Resize Text
- Text (but not images of text) can be resized up to 200% (without assistive technology) and doing so does not lose content or function
- 1.4.5 Images of Text
- Images are not used to achieve visual text effects if the same effect can be achieved in text except where it is a logo, the image is customisable by the user, or that particular presentation of text is essential to the information (for example, showing someone what an unusual font looks like would normally need to be done via images as people would be unlikely to have that font installed).
Level AA: Operability
There are only 3 operability success criteria at Level AA.
- 2.4.5 Multiple Ways
- Multiple methods must exist to locate an individual web page on a site (e.g. links in content, navigation, search, site map etc) unless that individual page is part of a process (e.g. you would expect to be able to find ‘place order’ but not ‘confirm order’ as this would have ‘place order’ as a pre-requisite)
- 2.4.6 Headings and Labels
- Headings and labels describe the topic or purpose in question
- 2.4.7 Focus Visible
- Any keyboard operable user interface has a mechanism for making the keyboard focus indicator visible (e.g. when you use
:hoverto make your sites look pretty on mouseover, do something with
:focustoo to benefit keyboard users).
Level AA: Understandability
There are 5 understandability success criteria at Level AA.
- 3.1.2 Language of Parts
- The human language of sub-parts of the phrase can be programmatically determined (I normally use something like
<i lang="lat">ad hominem<i>as it provides a visual as well as programmatically determinable cue). Exceptions are proper names, words of indeterminate language, and words or phrases that are in common usage in the language of the rest of the page
- 3.2.3 Consistent Navigation
- Navigation mechanisms that are repeated on multiple pages occur in the same relative order, unless the user has specified a change. In other words, don’t start moving your navigation panels around…
- 3.2.4 Consistent Identification
- Things that perform the same action on a set of pages are identified consistently. For example, don’t use submit/cancel and then enter/clear for the same purpose.
- 3.3.3 Error Suggestion
- If an error is automatically detected and possible corrections are known, suggest them unless that would go against the purpose of the content. E.g. if someone has selected ‘Moanday’, and you have the capability, it’s reasonable to suggest that they might have meant Monday, but if they are trying to log in with the user name ‘admin’, you might not want to suggest ‘did you mean password FZZBX?’…
- 3.3.4 Error Prevention (Legal, Financial, Data)
- For pages that cause legal or financial commitments, or modify user-controllable data, you must ensure that submissions are reversible, or that they are checked or confirmed by the user before finalising them.
Level AA Roundup
A number of the success criteria at level AA start to pose more difficult obstacles: if you are going to use live video, you’re going to need live captions and live audio description, which could pose considerable technical problems.
On the other hand, that’s why these guidelines weren’t included in level A. There are also a lot of success criteria which I think are good practice in here, and with the exception of people who are using synchronised video/audio, I see no reason why this couldn’t be a very realistic level to aim for that would bring a lot of benefits to users with disabilities without being too onerous to achieve.
Don’t get me wrong, I would like to see people with ’syncronised media’ content achieve this level too; I just think that in practice, a lot of them won’t. But even so there’s still no reason why they shouldn’t aim to achieve this standard for the non-video part of their site at least.
Published at DZone with permission of Schalk Neethling. See the original article here.
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