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[techs] "Rules" for data tables.

From: Jim Thatcher <jim@jimthatcher.com>
Date: Wed, 12 May 2004 12:06:56 -0500
To: "'WAI WCAG List'" <w3c-wai-gl@w3.org>
Message-ID: <001801c43843$9c22d7f0$6501a8c0@JTCOM2400>
At the end of today's call I said I agreed with the idea of the 


TH Rule (TH technique): TH shall be used for all data tables to identify
heading cells and TH shall not be used in Layout Tables. (By the way, if you
don't like the way the headings look in TH's, use style get them to look the
way you want.)


I want to add:


The Summary Rule: Use a non-empty summary attribute on all data tables to
summarize the table structure and use summary="" on all layout tables.


There is a huge difference between these two rules. I contend (with no data)
that most data tables are simple tables with headings in row 1 and column 1
- the "and" is important. The TH rule does not help screen readers identify
headings in this case because they read from row one and column one anyway.
On the other hand, the summary can be immensely helpful presenting a quick
view that a sighted user probably obtains by glancing at the table.


Note the summary can and should present information that will probably be
obvious to a person looking at the table - in contrast the Caption/Title
identifies the purpose of the table and may not be obvious to someone
looking at the table - it also adds to the visual experience.  This suggests


Caption Recommendation: Use the caption element to specify the purpose of
the data table and do not use the caption element on layout tables.


The Headers/Id Rule: If there are data cells in a data table whose heading
information does not lie in the same row and column as the data cell, then
use the header/id markup to identify the heading information for all data
cells of the table. 


The Scope Rule: Use the scope attribute to specify whether a headings
applies to a row or column when that information is ambiguous, such as being
at a corner of the table or inside the table.


I have no idea what the axis rule/recommendation is!




Accessibility, What Not to do: http://jimthatcher.com/whatnot.htm.

Web Accessibility Tutorial: http://jimthatcher.com/webcourse1.htm.

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Sailesh Panchang
Sent: Wednesday, May 12, 2004 8:33 AM
To: 'WAI WCAG List'
Subject: Re: [techs] The TH Rule


Jim writes:

>On the idea of display:none for the caption, I believe that >will hide from
JAWS and Window-EYES too.

Yes but when one uses the T command to jump from table to table with JFW or
WinEyes, it announces the caption. But not  if you scroll through  using
arrow keys.


Yes, Thanks about the  th in the corner cell. That was an error.

Received on Wednesday, 12 May 2004 13:07:38 UTC

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