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[Fwd: Re: Structure in Data-Tables]

From: Steven Dale <sdale@stevendale.com>
Date: Mon, 10 May 2004 13:57:22 -0400 (EDT)
Message-ID: <1860.>
To: <w3c-wai-ig@w3.org>

-------- Original Message --------
Subject: Re: Structure in Data-Tables
From: "Steven Dale" <sdale@stevendale.com>
Date: Mon, May 10, 2004 1:52 pm
To: <wrwilliams@fs.fed.us>

In accessibility, a table for fomatting a page is commonly referred to
as a layout table.  A table that marks up the structure of data in a
representative way (ie spreadsheets) is referred to as a data table.
Now, there are two types of data tables, simple and complex.  A simple
table consists of one set of headers for the entire table, these may be
column and row headers or just one of the two.  A complex data table
consists of multiple table headers where a data cell may be under one
set of headers but not another set.  (for an example see my complex
table at
http://mason.gmu.edu/~sdale1/PAF/ff/ )

It may be visually appealling to have a layout table inside a data table
cell, and I doubt this would cause a problem if the layout table was
linearized correctly.  CSS would perhaps be a better solution here.

I think if you were trying to put one data table inside another data
table, serious consideration ought to be done on what you are actually
trying to represent.  A properly marked up complex data table would be
easier to understand in a screen reader environment, where the table
headings pertaining to the cell would be read upon entering the cell.

Another point is that of consistancy.  One row of data might contain
different fields eg picture, name, link etc.  But each row should have
the same layout in a simple data table.


William R Williams said:
> It seems, at least to me, there are 2 areas of concern here:
> 1. In mentioning "datatables," my assumption is that you are asking
> about the presentation of data in a table format; i.e., to tabulate
> the data, or "tabular data." A strict definition of this, which
> existed pre-World Wide Web, is to condense, reduce or list the data
> ... to provide a synopsis. As I see it, block-level elements such as
> headings or paragraphs should not be used within a data cell if the
> "data" doesn't fit the technicalities for language use. For example, a
> paragraph typically consists of one or more sentences; and a sentence
> consists of a subject/verb combination. If a verb is missing in a
> fragment, such as you might see as a succinct or condensed entry in a
> table cell, how can one accurately mark-up the "data" as a paragraph?
> Conversely, if the "condensed" data is presented in a list of items,
> then <ul> or <ol> within a cell seems quite appropriate. Typically,
> however, the document structure is implemented in the table mark-up. I
> think this could be seen as a general guideline.
> 2. If the question actually regards the use of <table> for page
> layout, then why even consider its use when there are better options
> available today, such a CSS for positioning? I would pose this
> question despite one's contention that the table linearizes in a
> readable order. Yes, there are still some limitations to what you can
> do with CSS
> positioning, but 2, 3, 4 column layouts are possible and, with some
> creativity and diligence, you can accomplish about the same results as
> you might with the use of nested tables. Really, there should be a
> greater push to eliminate the use of the table tag for page layout.
> Thanks!
> Bill Williams
> "We had a discussion recently about the nature of datatables.
> The question is, which html-elements and which contents are allowed
> inside a
> data-table, too keep it as accessible and as flexible as possible.
> And: Should text- structure elements be allowed (p, li, ul, ol)
> ...
> Definitely forbidden:
> Tables!"
Received on Monday, 10 May 2004 13:58:21 UTC

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