- From: Gregg Vanderheiden <po@trace.wisc.edu>
- Date: Thu, 18 Jun 1998 13:12:42 -0500
- To: "'GL - WAI Guidelines WG'" <w3c-wai-gl@w3.org>
This looks like it should be on this list so I am moving it over here for discussion Gregg ---------------------------- to follow up on what Josh Krieger said: > I am trying to understand more about how to use the SCOPE > and HEADERS attribute for labeling table cells. The > examples at the end of the authoring guidelines are for > very simple tables and I wonder about how these would > really apply to many of today's tables that are used > for layout. Is it even appropriate to use these attributes > for layout based pages considering this is against the ethos > of the working guidelines? I have to admit, I'm finding > these attributes confusing. It is not appropriate to use SCOPE and HEADERS for layout tables. These are to be used when one cell (de_facto header) gives generic inforation about one or more other cells. Pure layout tables don't have these logical relationships between cells in the grid. > In particular, I don't understand how to do labeling > when using: 1) nested tables, 2) column and/or row groups. > And I don't have a clear idea when I would really want > to use the HEADERS, the SCOPE, or the more general AXIS. > In many ways, the AXIS attribute seems less about > accessibility, and more about alternative views > of the data. For nested tables, I would have to see what it is used for to comment. For column or row groups you may use AXIS to construct a category hierarchy. That is, use AXIS if you have second-order metadata visible in the table. Yes, it is about alternate views. It was supported by the WAI reviewers, not invented by them. Alternate views have proved helpful in audio browsing of complex tables in some (not exhaustive) experiments. > I'm wondering if anyone has prepared a more comprehensive set > of examples using these attributes, or if anyone has > implemented a simple text-based table browser that is designed > to help work with these issues. All the HC work is still public. If you don't find what you want in terms of a life-size example in the final HTML 4 language, you may find it helpful to review the discussion for some interpretation. This just gives you a rough orientation to the general ideas. This is a good topic for the page authoring subgroup list. Al Start at http://www.w3.org/WAI/HC/report.html to work you way back into the TABLE materials. ------------------------------------------ Concerning nested tables: SCOPE and HEADERS can refer only to cells of the _same_ table in which they appear. A nested table is a content of a cell of a table. It is impossible to refer to it from a cell of the nesting table exactly as it is impossible to refer to a list or a paragraph in a particular cell. Regards. Nir Dagan Assistant Professor of Economics Universitat Pompeu Fabra Barcelona (Spain) email: dagan@upf.es Website: http://www.econ.upf.es/%7Edagan/
Received on Thursday, 18 June 1998 14:21:27 UTC