April 2012 Standards Update
The DIAGRAM Content Model (NISO Z39.98-2012: Authoring and Interchange Framework for Adaptive XML Publishing Specification, http://www.daisy.org/z3998/2012/z3998-2012.html) has stabilized, with issues being tracked at the Google code site at this link: http://code.google.com/p/zednext/issues/list. As a next step, we are considering reference implementations of the content model in reading software, in order to provide additional guidance for implementers who wish to support content model descriptions for end-users.
In the meantime, the fate of longdesc, an attribute that can be used to support references to external image descriptions in HTML 5, remains unclear. A decision on longdesc was expected in April from W3C, but the DIAGRAM Content Model Working Group has not been optimistic that the outcome would be favorable. The next public draft of HTML 5 would thus trigger a revision to the EPUB 3.0.1 for which DIAGRAM has proposed the use of the epub:describedAt attribute to support reference to the content model.
On April 11, the Content Model Working Group also heard a presentation from Ed Summers and Julianna Langston at the SAS Institute, where they are contemplating development of a language to capture a semantic description of a graphic or chart or diagram. Dubbed “ChartML” for now, the semantic description would be mode agnostic; not specific to vision, svg, etc., but rather represent the underlying structure of data visualization so that a graphic could be rendered in a way that adapts to the ability of the user and the capabilities of the device she’s using to view. Ed, who is also a member of the DIAGRAM Tactile Graphics Working Group, has also formed the Accessible Infographics community group at W3C to contribute to this work. Matt Garrish, on the DIAGRAM Content Model Working Group, is also a member. We look forward to seeing this work evolve and fostering the interconnections between the proposed “ChartML” and DIAGRAM’s efforts.