Re: ARIA Graphics Module -- proposed roles hierarchy & data properties

As promised, I have updated the proposal summary and put it on the wiki:
https://www.w3.org/wiki/SVG_Accessibility/ARIA_roles_for_charts

It incorporates all the little changes I've discussed so far, along with a
new `aria-dataproperty` attribute for defining which visual aspect of the
graphic is affected by each data variable, as a list of CSS style
properties or XML attribute names.  This seemed to me the best way to
create a machine-interpretable description that was also flexible to any
chart design.  However, I'm sure there are complications to consider.


You'll want to compare with Fred's Chart taxonomy summary, also on the
wiki: https://www.w3.org/wiki/SVG_Accessibility/Chart_Taxonomy

I've also put together a wiki page of discussion, starting by copying
comments from the mailing list discussions of the past month:
https://www.w3.org/wiki/SVG_Accessibility/ARIA_chart_taxonomy_discussion

I still want to create some more example graphics (and update the ones I
did last week to reflect the conversations we've had).  I probably won't
get to it until the end of the week.

Best,
Amelia