Kinds of rule in Tanaguru

mfaure's picture

Rules are divided in different kinds depending what can be automatized

Decidable rules

Decidable rules can always give a result. The result is one of Passed, Failed or NA (Not Applicable).

Example: rule for AccessiWeb 1.1.1 (alt presence on img elements)

Semi-decidable rules

Semi-decidable rules can give a result depending on the "situation", i.e. the observed HTML. Semi-decidable (SD) rules include different sub-kinds.

"SD-failed" rules

The "SD-failed" rules can give a result that is one of Failed, NMI (Need More Information) or NA.

Example: rule for AccessiWeb 1.3.1 (alt relevancy for images that convey information)

Rules with suspected results

As we want Tanaguru to be "200%" reliable for the user, we prefer giving the user some clues to find the good result than pretending results that could be false-positive ones. This is the reason why we created the Rules with suspected results.

This kind of rule gives a result that is part NA or NMI (with informations about suspected elements).

Example: rule for AccessiWeb 7.5.1 (scripts generating change of context without warning the user)

Detection rules

Detection rules detect the presence of an element (without doing any other test), enabling the user to lower the remaining manual work. Therefore the given results are part of NA or NMI

Example: rule for AccessiWeb 6.5.1 (alternative content for server-side image map)

Benefit for the user: if the audited website contains no form, user can securely bypass all rules about forms (result is NA for the whole theme).

Rules with markers

Rules with markers are provided with data given by the user before the audit. Such information (called marker) can help Tanaguru increase the automation level.

Markers are not related to decidability.

Example: rule for AccessiWeb 5.4.1 (caption presence on data table)