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Re: PF Response: @Summary

From: Leif Halvard Silli <lhs@malform.no>
Date: Thu, 04 Jun 2009 14:47:47 +0200
Message-ID: <4A27C273.9030704@malform.no>
To: James Graham <jgraham@opera.com>
CC: joshue.oconnor@cfit.ie, Laura Carlson <laura.lee.carlson@gmail.com>, Ian Hickson <ian@hixie.ch>, Janina Sajka <janina@rednote.net>, Sam Ruby <rubys@intertwingly.net>, Chris Wilson <Chris.Wilson@microsoft.com>, Michael Cooper <cooper@w3.org>, Dan Connolly <connolly@w3.org>, Mike Smith <mike@w3.org>, W3C WAI Protocols & Formats <w3c-wai-pf@w3.org>, Gez Lemon <gez.lemon@gmail.com>, "wai-liaison@w3.org" <wai-liaison@w3.org>, John Foliot <jfoliot@stanford.edu>, www-archive <www-archive@w3.org>, public-html@w3.org
James Graham On 09-06-04 13.11:
> Joshue O Connor wrote:
>> On Wed, 3 Jun 2009, Ian Hickson wrote:
>>>> Is the need not served by <caption>?
>>
>>> No. A caption is provided visually. [...]
>>
>> It is also worth noting that <caption> is a terse descriptor. @summary
>> is a long descriptor.
> 
> Since this is clearly going to be a long discussion it might help (and 
> would certainly help me) if we start from clear premises. So it would be 
> great if statements like "<caption> is..." could be clear about whether 
> they are referring to spec requirements, actual author practice, some 
> sort of best practice (that may or may not match actual common 
> practice), or something else, along with pointer to the relevant 
> documentation/evidence.
> 
> In this case I can't see anything in a HTML spec to back up your claim 
> that <caption> must be terse whilst @summary must be long. 

HTML 4.01 on @summary (versus <caption>):

[1][2]: "summary [...] purpose/structure for speech output"

[3]: "Each table may have an associated caption (see the CAPTION 
element) that provides a short description of the table's purpose. 
A longer description may also be provided (via the summary 
attribute) for the benefit of people using speech or Braille-based 
user agents."

[4]: "summary = text [CS]
	This attribute provides a summary of the table's purpose and 
structure for user agents rendering to non-visual media such as 
speech and Braille."

[4]: "The following informative list describes what operations 
user agents may carry out when rendering a table: Make the table 
summary available to the user. Authors should provide a summary of 
a table's content and structure so that people using non-visual 
user agents may better understand it."

[5]: "When present, the CAPTION element's text should describe the 
nature of the table.[...]
	Visual user agents allow sighted people to quickly grasp the 
structure of the table from the headings as well as the caption. A 
consequence of this is that captions will often be inadequate as a 
summary of the purpose and structure of the table from the 
perspective of people relying on non-visual user agents.
	Authors should therefore take care to provide additional 
information summarizing the purpose and structure of the table 
using the summary attribute of the TABLE element. This is 
especially important for tables without captions. Examples below 
illustrate the use of the summary attribute."

[6]: "summary of table contents"

[6]: "table [...] summary of contents"

[7]: "Section A.1.3 (previously A.3)
	The longdesc attribute was said to be specified for tables. It is 
not. Instead, the summary attribute allows authors to give longer 
descriptions of tables."

[7]: "A.3.3 Changes for accessibility [...]
	Authors may provide long descriptions of tables (see the summary 
attribute), images and frames (see the longdesc attribute)."

> In general it 
> seems problematic to require that caption be terse because certain types 
> of documents inherently have long table captions; scientific papers 
> often put a paragraph or more of text in the table caption explaining 
> how to read the table, for example.


HTML 5 has the <figure> element, which has its own caption 
element. The need for "caption groups" (analogy to <hgroup>) could 
eventually be served by e.g. placing a paragraph between the 
figure caption and the table - for example.


[1] http://www.w3.org/TR/html4/index/attributes
[2] http://www.w3.org/TR/html4/sgml/dtd
[3] http://www.w3.org/TR/html4/struct/tables#h-11.1
[4] http://www.w3.org/TR/html4/struct/tables#h-11.2.1
[5] http://www.w3.org/TR/html4/struct/tables#h-11.2.2
[6] http://www.w3.org/TR/html4/index/list
[7] http://www.w3.org/TR/html4/appendix/changes
[8] 
http://www.whatwg.org/specs/web-apps/current-work/multipage/tabular-data.html#the-caption-element
-- 
leif halvard silli
Received on Thursday, 4 June 2009 12:48:34 GMT

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