W3C home > Mailing lists > Public > w3c-wai-gl@w3.org > April to June 1998

Table Labels

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>
Message-ID: <000801bd9ae4$afb46ca0$a2181a26@vanderheiden>
This looks like it should be on this list so I am moving it over
here for discussion


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
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
This just gives you a rough orientation to the general ideas.
This is a good topic for the page authoring subgroup list.
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.
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

This archive was generated by hypermail 2.3.1 : Tuesday, 16 January 2018 15:33:27 UTC