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Re: More about <alt>

From: Robert Burns <rob@robburns.com>
Date: Thu, 6 Sep 2007 14:47:29 -0500
Message-Id: <8D98BED9-1211-49BD-BCA7-11F781919269@robburns.com>
To: public-html@w3.org

Hi Sander,

On Sep 6, 2007, at 7:59 AM, Sander Tekelenburg wrote:

>
> At 14:03 +0200 UTC, on 2007-09-06, Olivier GENDRIN wrote:
>
>> On 9/6/07, Sander Tekelenburg <st@isoc.nl> wrote:
>
> [...]
>
>>> <img id="mergedcells" src="mergedcells.gif">
>>> <!-- anything or nothing -->
>>> <alt for="mergedcells" title="short textual equivalent"
>>> type="text/html">blah</alt>
>>> <alt for="mergedcells" title="long description" type="text/ 
>>> html>blah,
>>> blah</alt>
>>> <alt for="mergedcells" title="tabular equivalent" type="text/html">
>>> <table border="1" summary="This table gives some statistics about  
>>> fruit
>>> flies: average height and weight, and percentage with red eyes  
>>> (for both
>>> males and females).">
>>> <caption><em>A test table with merged cells</em></caption>
>>> <tr><th rowspan="2"><th colspan="2">Average
>>>     <th rowspan="2">Red<br>eyes
>>>     <tr><th>height<th>weight
>>>     <tr><th>Males<td>1.9<td>0.003<td>40%
>>>     <tr><th>Females<td>1.7<td>0.002<td>43%
>>> </table>
>>> </alt>
>>
>> Ok, I understand better what you meant. But in that case, I wish that
>> your 3 titles where replaced by an attribute that would said :
>> 'alternative', 'short description', 'long description' (@role ?).
>
> I don't think @title needs to be removed, even if predefined values  
> would be
> added thropugh @role. @title might then be less necessary, but  
> might still be
> useful, right?
>
> As to predefined values itself: I can see that such a thing might  
> be useful.
> I'm trying to hold it off though, because I suspect that there is  
> no limit to
> the sort of equivalents authors might want to provide. It doesn't seem
> realistic to me that we can think ahead of descriptive terms that  
> will cover
> all situations. So even we we define some generic predefined values  
> like
> "short", "long", "audio", "captioned video", etc. we would still  
> have to
> allow authors to use some non-predefined value: "table", "slide",  
> "pdf",
> ".doc", "x", "y", "z".

I do not think 'long' or 'short' is very useful.. Most of these  
others examples fall into the 'type' or potentially 'role' categories.

> Note that in the <alt> proposal, @type is required already, and UAs  
> are
> required to make that available to users, preferably translated into a
> user-friendly form.
>
> I haven't yet given much thought to the specifics if MIME types in  
> this
> context though. Possibly not all MIME types will be indicative  
> enough. Any
> thoughts on that, anyone?
>
> Clearly audio/ogg, audio/mpg, audio/mp3, etc. would allow the UA to  
> indicate
> that the equivalent is aural. But does the same apply to vague  
> container
> formats such as .avi and .mov?
>
> What can probably not be indicated through @type is something like a
> captioned video. Can we think of more such cases? (The more there  
> are, the
> more important it gets that authors provide useful @titles, which  
> they might
> get wrong, which would increase the need for something like @role.)

.mov and .avi are not mediat types; they are filename extensions. All  
media types are going to begin with either text/, audio/, video/',  
application/ etc. The media types are not only insufficient to convey  
what accessibility information may be encoded in the type, but also  
they do not convey the codec used. The @role attribute would be  
useful these sorts of information. The title could be used as a last  
tier attribute to distinguish further between alternates that shared  
the same @type and @role.
Received on Thursday, 6 September 2007 19:47:49 UTC

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