accessible diagrams

Hi folks

I was meant to look into the ways to make diagrams truly accessible

Unfortunately the best ways were to use XHTML 2.0 with taxonomies or RDF.....
But... we could mimic something using css and a text explanation of classes.

This is my attempt

step a: If we identifier key aspects of accessible diagramed modeling (see bellow)  and then
b,  we can create a technique were key model components such as path and  varsities are given specific and consistent class names, and 
c,a note is added that explains what the class represents (like a key). The key needs to be before the diagram.

Assistive technology could then follow paths through a diagram or give options to jump to clusters etc.... 

Clearly in XHTML 2.0 and RDF this could all be extracted programmatically

Step a: Overview of building a model for accessible diagrams
My feeling is the general model is state forward, however boiling the model up to include enough examples before anyone need to create their own roles will take time and research.

The suggested model:
>From the examples we had I saw two core roles. they were
a, Node (such as a server box, a flow chard box, a subway station)
and
b, varsity or connection  (such as subway lines, internet links, connectivity, flow to arrows, bi-directional arrows , servers, or terminals)

Taking typical diagrammatic  usecases we could build this into a full set of instances or inherited roles.


As we fill it in we may find things missing , such as a state/properties for direction /bi-directional of a varsity it may be useful to have a role for Clusters (a group of nodes)

An interesting one would be  path- such as a group of varsities or connections that will take you through a concept (such as a subway line in a diagram, or a theme in a book)

Flags (maybe as a second class) could be added to fill in node information such as potential start of a path, availability of accessible bathrooms at a station etc.
  

All the best
Lisa