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Re: summarization information delivery options: attribute or element

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Sat, 27 Feb 2010 03:37:13 +0100
To: Laura Carlson <laura.lee.carlson@gmail.com>
Cc: Shelley Powers <shelleypowers@burningbird.net>, Gez Lemon <g.lemon@webprofession.com>, John Foliot <jfoliot@stanford.edu>, "Gregory J. Rosmaita" <oedipus@hicom.net>, public-html-a11y@w3.org
Message-ID: <20100227033713486679.a7caa5bc@xn--mlform-iua.no>
Laura Carlson, Fri, 26 Feb 2010 13:27:41 -0600:
>> I have never heard Gez include "purpose" when he describes what 
>> @summary is for.
> 
> Purpose of the summary Attribute by Gez Lemon, 10th June 2009.
> http://juicystudio.com/article/purpose-of-the-summary-attribute.php


Thanks for the pointer. Gez said there:

	]]The HTML 4.01's definition of the summary attribute  uses the term 
purpose in its definition, which, along with the summary attribute's 
name, seems to have confused the purpose of the summary attribute.[[

But I am not sure he can totally escape the fact that HTML401 does 
mention "purpose" as one of the purposes of @summary. It says so many 
times, in fact. E.g. just look in the DTDs: "purpose/structure for 
speech output".

Gez also said there:

	]]The summary attribute is not intended to provide a long description 
for data tables.[[

However, there can not be any doubt that HTML401 *does* say that 
@summary can be used for a long description - HTML4 holds the idea that 
those that need @summary also needs longer descriptions than <caption> 
typically provides:

	]] A longer
   description may also be provided (via the summary attribute) for the
   benefit of people using speech or Braille-based user agents.[[

As to what I said about how @summary relates to <caption>, then I find 
it interesting that the place were @summary is described perhaps the 
best - and most! -  is in the section about the caption element. I will 
quote everything about summary from that section:

]]
 11.2.2 Table Captions: The CAPTION element
[…]
 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.
[[

I find it entirely convincing that HTML401 talks about purpose. I think 
that the role of @longdesc, when applied to a <iframe> or <frame> is 
also to (better) explain the purpose of of the (i)frame, so that the AT 
user can decided whether it is worth it to dig into them.

As for summary, then HTML401 has 9 examples of use of @summary. One of 
them goes like this:

]]
<TABLE border="2" frame="hsides" rules="groups"
          summary="Code page support in different versions
                   of MS Windows.">
<CAPTION>CODE-PAGE SUPPORT IN MICROSOFT WINDOWS</CAPTION>
[[

The only extra information in @summary is "different versions of". This 
is not about structure,  is it? But it it is a word about the purpose. 
And I would argue that "different versions of" adds some extra info 
that can be useful - without that info, then it is not possible to know 
that the purpose of the table is to *compare* different versions of 
Windows - as opposed to simply list what the current Windows version 
supports.
-- 
leif halvard silli
Received on Saturday, 27 February 2010 02:37:50 GMT

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