Comments on draft chart taxonomy

Here are my comments on Fred’s draft, which largely reflect discussions over the last several weeks.

There are roles in the proposal that largely correspond to existing ARIA roles: graphics-document is similar to the ARIA document role; graphics-object is similar to the group role. The principal difference seems to be that the content is designated as graphical. If assistive technologies can easily infer that the content is graphical, then it may be feasible to use the existing ARIA roles without defining new (and similar) ones, as here.

I think the semantics of the aria-gtype property should be clarified. In particular, it may duplicate the functionality of the aria-roledescription property of ARIA 1.1, in which case, reusing the latter would be preerable to introducing a new property. In general, if the type of entity to which ARIA roles, states and properties are applied needs to be distinguished in a systematic, machine-readable fashion, then this really ought to be accomplished by defining a specific role rather than by using a more general role and a property associated with   the element to  do so. The purpose of aria-roledescription is simply to give a localized string to the AT that can be presented to the user to characterize the type of element, without implying any difference in purpose or behavior from the underlying ARIA role. This mechanism is desirable, of course, and respects the principle articulated above.

It was widely agreed at the meeting two weeks ago that the author should be permitted, though not required, to specify the value of each data item explicitly. For example, a property could be defined to take comma-separated values to specify each data point. I think this is desirable functionality that should be integrated into the draft.

I also concur with Doug’s misgivings about the term “guide”, though I don’t have a markedly superior alternative to offer for the envisaged superclass role.


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Received on Monday, 3 August 2015 16:30:55 UTC