Accessibility Valet Reports
Accessibility Valet offers a range of report options, as discussed elsewhere in the Help pages. However, the basic information is the same regardless of the option selected:
- A summary result
- A representation of the document's markup
- Individual accessibility test results
The Summary Result indicates whether a page conforms to the selected accessibility guidelines. There are five possible results:
- Pass - The automatic analysis found nothing at all to worry about. A straight pass is rare at any test level above WCAG Single-A (although it is of course automatic if you select no accessibility test suite at all).
- Probable Pass - One or more possible violations were found, but there is only a small risk that any of them will be found to be actual violations when you review them.
- Possible Pass - There is a significant danger that some of the warnings may indicate actual violations. You should think carefully before accepting the page as OK.
- Probable Fail - There are warnings that need your attention, and probably mean a violation of the guidelines. But after careful consideration you may nevertheless satisfy yourself that the page complies with the guidelines.
- Fail - The automatic analysis found violations of the selected standard with certainty. You should definitely fix it. Note that at WCAG Level AA or higher, any invalid or deprecated markup in the page will cause an automatic fail against Checkpoint 3 of the guidelines.
Note that the result is always subject to the limitations of automatic testing and the need for human judgement (as discussed in the introduction).
The Accessibility Valet analysis builds a document tree from the markup in a page (this is also how most web browsers work)! The Valet reports include a representation of the document tree. The static HTML report options show it as normalised markup in full, whereas the DOM Browser and EARL options represent it as Elements and Attributes with a "Node" relationship - shown in the browser as a document tree.
Bogus and Deprecated Markup
Though not a formal validator like Page Valet, Accessibility Valet knows the structure of HTML 4 and XHTML 1, including the Elements and Attributes, and their permitted relationships (i.e. where an Element or Attribute can or can't appear). This knowledge is used to highlight bogus and deprecated markup in the report.
Accessibility Valet applies a series of constraint-based tests to HTML Elements and Attributes. This is originally inspired by Schematron's constraint-based testing, but generalises it with an object-oriented test model capable of arbitrary processing (schematron only tests whether something is present or not) and is fully integrated with the document tree.
Whenever a constraint-based test is failed, Valet inserts a warning into the report, either at the point of failure or in a separate list referencing the point of failure according to the report option selected. Tests that are passed are not reported.
For details of individual warnings, see the list of warnings.