SVG markup thoughts

Rich,

I think it is important to be able to inherit the semantic role from an
ancestor for three reasons. Semantic inheritance avoids bloat, it keeps
authors from going nuts and simplifies guidance. Whenever you bloat your
resource, products will argue against a bloated resource because it loads
slower and takes more memory. We need to allow inheritance from any level
of ancestor as intermediate groups are often generated for a change in
style. For example, in the airline (delay) chart, the grid lines for the
months are grouped by location of the text. These groupings are are more
space saving than putting the attributes in each grid line and we should
not discourage non semantic groupings.

In my markup, when groups should be part of navigation, I provide one (or
possibly two) of - title, desc, aria- label, labeledby or describedby. Non
semantic grouping (like the airline chart month grid lines for text
location) don't have a title, desc, aria- label, labeledby or describedby
and are ignored by navigation.

I am doing markup to support navigation and AT interpretation.  Markup for
media query style changes for low vision, color blind and coga will come
later. In navigation experiments, regardless of the type of graphic, if you
have groups that represent features, reasonable things happen (using a tree
style navigation) when the groupings are done well.

So if it will be a problem to allow role attribute inheritance, then I
suggest we create a semantic role or graphic role (g-role) attribute.
                                                              
                                                              
                    Regards,                     Fred         
                                                              
                   Fred Esch                                  
       Accessibility, Watson Innovations                      
    AARB Complex Visualization Working Group                  
                     Chair                                    
        W3C SVG Accessibility Task Force                      
                   IBM Watson