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Re: Some questions about data tables

From: Charles McCathieNevile <charles@w3.org>
Date: Mon, 3 Jan 2000 03:27:31 -0500 (EST)
To: Janet Parkinson <janet@dunshelt1.freeserve.co.uk>
cc: w3c-wai-ig@w3.org
Message-ID: <Pine.LNX.4.20.0001030325040.7549-100000@tux.w3.org>
Janet,

as I understand it you are correct in your simple example - that will
linerise nicely. I am not sure what there is implemented within browsers - I
suspect not much to judge by the discussions in the User Agent Guidelines
list, but there is a tablin tool developed by W3C through the WAI-ER group -
http://www.w3.org/WAI/ER/IG - to lineraise tables, which provides various
methods of linearising tables and choosing which headers should be included.

cheers

Charles McCN

On Wed, 22 Dec 1999, Janet Parkinson wrote:

  I have some questions concerning the design of data tables. I was wondering
  if anyone would be able to give me any answers on them? There are three -
  
  1 What is the proportion of screen readers that are currently capable of
  associating headings and data cells by reading the mark-up of a table?
  
  2 - single and two level tables
  
  single level tables  - table follows
  
  Bus Times for different days:
  
  Saturday      9    12   13
  Sunday       10   13    14
  
  According to the accessibility guidelines all that is required to make this
  accessible is to mark up the headings properly, it is not necessary to use
  'scope' attributes or other tabular mark-up (Guideline 5.1 & 5.2). The
  accessibility guidelines do not mention the need to ensure the linearisation
  of data tables, only layout tables (guideline 5.3). Am I right in assuming
  that this table will satisfy the accessibility guidelines with the correct
  headings marked up?
  
  2 level tables - table follows
  
  Bus Times, columns refer to places, rows refer to days of the week
  
  Day           London  Manchester    Leeds
  Saturday       9             12                  13
  Sunday         10           13                  14
  
  The accessibility guideline 5.2 states that tables with 2 or more logical
  levels should be marked up to indicate the logical relationships between
  cells. So here I assume that by marking up both column and row headers with
  'scope' attributes, the necessary relationships would be in place.
  
  The problem I have here is that I don't know the level of support of current
  screen readers for the 'scope' attribute, or the other attributes added by
  the HTML 4 specification. Does anyone know of any research that has been
  done in this area?
  
  3 - Automatic assumption of relationship between headings and cells
  
  Are there any screen readers which are capable of associating headings by
  assuming an association with the column or row to which it refers without
  any extra mark-up? It was my thought that in most cases the association of
  headings and cells was self-evident and so it could be automatically
  assumed. The heading in the corner of my table would cause some confusion as
  the relationship to cells is not self-evident there. However assuming the
  association in the other cases would give some extra information
  automatically. Any thoughts?Accessible generation of tables -
  
  

--
Charles McCathieNevile    mailto:charles@w3.org    phone: +61 409 134 136
W3C Web Accessibility Initiative                    http://www.w3.org/WAI
21 Mitchell Street, Footscray, VIC 3011,  Australia (I've moved!)
Received on Monday, 3 January 2000 03:27:39 GMT

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