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RE: linearized tables

From: Jon Gunderson <jongund@ux1.cso.uiuc.edu>
Date: Tue, 14 Mar 2000 09:41:06 -0600
Message-Id: <4.1.20000314092913.00abb940@staff.uiuc.edu>
To: thatch@us.ibm.com
Cc: w3c-wai-gl@w3.org

There are three major categories of tables in my mind:

1. Tables that are used purely for layout and are indicated with no header
markup or caption information.  The summary attribute may read "layout".
Simple linearization of these tables results in a readable document.

2. Tables that are used for tabular information (like the TV guide) and use
proper heade markup and should have a defined caption element.

3. Tables that contain tabular information and do not use proper header
markup or header markup is incomplete.  There is not much UA or AT can do
for these tables for proper lineraization or translation to speech or
Braille.  Unfortunately this is the most common type of table in usage today.


At 09:01 AM 3/14/00 -0600, thatch@us.ibm.com wrote:
>How do you distinguish tables used for layout and those for tabular data? I
>think the distinction is when the row-column position has meaning.
>TV listings, for example, are "tabular data." The layout of tabular data
>lets the sighted user observe the row-column semantics. Layout and tabular
>data get kind of mashed together.  I think (hope) no one is arguing that
>tabular data needs to linearize well.  Instead, use appropriate table
>markup, TH elements and headers attributes, summary attribute and caption
>The example of a form whose input elements are placed in a table with
>labels in the cells above is tabular data because row-column position
>carries meaning. Clearly tabular data is not restricted to numbers. TV
>Listings have very few numbers. The Form example is no less a table than
>the TV listings. The Form example is properly marked up if appropriate
>table markup is used. Of course the form can also be marked up with the
>LABEL element.
>My bottom line is that when row-column position carries meaning, then
>linearization is not relevant.
>Jim Thatcher
>IBM Accessibility Center
>After 3/31/2000 jim@jimthatcher.com (512)306-0931
>"Gregg Vanderheiden" <gv@trace.wisc.edu> on 03/13/2000 08:46:25 PM
>Please respond to gv@trace.wisc.edu
>To:   "'Greg Lowney'" <greglo@microsoft.com>, "'Wendy A Chisholm'"
>      <wendy@w3.org>, w3c-wai-gl@w3.org
>cc:   kasday@acm.org
>Subject:  RE: linearized tables
>Hi Greg,
>I think the problem is that most programs linearize by listing the items in
>the order they are appear in the HTML.  So labels above items would not
>linearize in any very usable fashion.
>This is not a problem with tables that present tabular information.  In
>case - the column headers across the top (If appropriately marked) would be
>the proper way to lay out a table.  (especially since there are usually
>labels down the side too.)  Not that the linearization rule does not apply
>to tables used for tabular information.
>It WOULD be a good idea for programs that linearize tables to give the user
>the option to flip it top-for-side to see if it were easier to understand
>use in that manner.  I don't know which ones do that though.   Anyone know
>of table linearizers with a flip layout function?
>-- ------------------------------
>Gregg C Vanderheiden Ph.D.
>Professor - Human Factors
>Dept of Ind. Engr. - U of Wis.
>Director - Trace R & D Center
>Gv@trace.wisc.edu, http://trace.wisc.edu/
>FAX 608/262-8848
>For a list of our listserves send "lists" to listproc@trace.wisc.edu
> -----Original Message-----
>From:     w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org]  On
>Behalf Of Greg Lowney
>Sent:     Monday, March 13, 2000 11:46 AM
>To:  Wendy A Chisholm; w3c-wai-gl@w3.org
>Cc:  kasday@acm.org
>Subject:  RE: linearized tables
>Hi Len, I don't necessarily disagree that it should be priority 1 to make
>tables understandable when linearized, but I don't like the example: "a
>laid out in a table with field labels on the top row and corresponding
>fields on the bottom row."
>I believe that complies with the guideline that requires the table to make
>sense when linearized. It is normal table behavior for the first row to
>label the entire columns, so from the standpoint of the guideline regarding
>linearization it should be OK to create a table whose first row contained
>labels for the form controls in lower rows. The responsibility then is on
>the agent doing the linearization to clearly express the labeling
>relationship between the column header and the cell contents. That's
>true whether the cell contains a control or any other content. Therefore I
>don't see the example as violating this guideline.
>However, the example would violate a second guideline, which is to ensure
>that implicitly-associated labels are properly positioned. That is Pri 2
>because it's assumed that the author will comply with the third guideline,
>that of providing explicitly-associated labels.
>     Greg
>-----Original Message-----
>From: Wendy A Chisholm [mailto:wendy@w3.org]
>Sent: Friday, March 10, 2000 12:08 PM
>To: w3c-wai-gl@w3.org
>Cc: kasday@acm.org
>Subject: Fwd: linearized tables
>>Resent-Date: Fri, 10 Mar 2000 11:39:32 -0500 (EST)
>>X-Sender: kasday@pop3.concentric.net
>>X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.2
>>Date: Fri, 10 Mar 2000 11:41:49 -0500
>>To: "wai-wcag-editor@w3.org" <wai-wcag-editor@w3.org>
>>From: "Leonard R. Kasday" <kasday@acm.org>
>>Cc: w3c-wai-er-ig@w3.org
>>Subject: linearized tables
>>Resent-From: w3c-wai-er-ig@w3.org
>>X-Mailing-List: <w3c-wai-er-ig@w3.org> archive/latest/1144
>>X-Loop: w3c-wai-er-ig@w3.org
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>>Resent-Sender: w3c-wai-er-ig-request@w3.org
>>WCAG says
>>5.3 Do not use tables for layout unless the table makes sense when
>>linearized. Otherwise, if the table does not make sense, provide an
>>alternative equivalent (which may be a linearized version). [Priority 2]
>>This means that someone could use tables for layout in way that the page
>>makes no sense and is not usable by any of todays user agents... but still
>>get an A conformance rating, because this is only priority 2.
>>For example, if there's a form laid out in a table with field labels on
>>the top row and corresponding fields on the bottom row.
>>I think the checkpoint needs to be Priority 1.
>>Leonard R. Kasday, Ph.D.
>>Institute on Disabilities/UAP, and
>>Department of Electrical Engineering
>>Temple University
>>423 Ritter Annex, Philadelphia, PA 19122
>>(215) 204-2247 (voice)
>>(800) 750-7428 (TTY)
>wendy a chisholm
>world wide web consortium
>web accessibility initiative
>madison, wi usa
>tel: +1 608 663 6346

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Chair, W3C WAI User Agent Working Group
Division of Rehabilitation - Education Services
College of Applied Life Studies
University of Illinois at Urbana/Champaign
1207 S. Oak Street, Champaign, IL  61820

Voice: (217) 244-5870
Fax: (217) 333-0248

E-mail: jongund@uiuc.edu

WWW: http://www.staff.uiuc.edu/~jongund
WWW: http://www.w3.org/wai/ua
Received on Tuesday, 14 March 2000 10:43:34 UTC

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