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More on <CAPTION> element etc

From: Joshue O Connor <joshue.oconnor@cfit.ie>
Date: Thu, 21 Jun 2007 10:06:52 +0100
Message-ID: <467A3FAC.3010103@cfit.ie>
To: public-html@w3.org

Ben Boyle wrote:
>> The idea that the table summary should be accessible in visual media
>> is good.

FWIW while using the summary attribute in this way may benefit the
sighted user by helping them understand the purpose or content of a data
table, and I am all for aiding comprehension, it is not *vital* as many
sighted users can without too much effort on their part get an overview
of the contents of the table by visually scanning it. The summary
attribute has been stepping in and acting as this 'quick scan' feature
for non sighted users - quite successfully I may add.

>> Many tables benefit from some extra explanation (i.e. a summary) about
>> their structure. This can be useful to everyone, if it is not limited
>> to "non-visual media". I believe this is what the WCAG Samurai refer
>> to in their advice.

You are probably right - so in that light - I can see the reasoning
behind it. To comment further though - this feature would be *nice* for
visual users but it is *vital* for blind users. It could also be really
useful for users with cognitive impairments to facilitate understanding
of the table contents, and I am all for that.

>> But if use something outside the <table>, something other than
>> table@summary, then that information isn't explicitly associated with
>> the table (and it becomes more difficult for AT to make that
>> association). 

The CAPTION element is supposed to do this but I have found its
application to be hit and miss, for example the CAPTION element may be
at the end of the table so the user may have already explored the table
before they get to the caption. IMO if it is used it should be at the
top. It can of course be successfully placed at the top in the source
order but styled to appear at the bottom [1]. Bear in mind that screen
reader users will have the facility to extract a list of relevant
tables, navigate them and select the one they want, they can also
quickly skip from table to table and the CAPTION element can easily be
missed if not placed correctly. Using this method of quickly browsing
tables does give @summary greater leverage in terms of use and better
enhanced usability for screen reader users. Also, the CAPTION is often
not announced by the user agent, its just read out. This is a UA issue
though and not a fault in the spec. So I find @summary to be better for
non-visual users. It is announced by the UA and is outputted
automatically when the table has UA focus.

Josh

[1] http://www.w3.org/TR/CSS21/tables.html#propdef-caption-side
Received on Thursday, 21 June 2007 09:07:11 UTC

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