W3C home > Mailing lists > Public > public-html@w3.org > July 2007

Re: conflation of issues or convergence of interests?

From: Lachlan Hunt <lachlan.hunt@lachy.id.au>
Date: Sat, 28 Jul 2007 17:30:25 +1000
Message-ID: <46AAF091.7010302@lachy.id.au>
To: Lachlan Hunt <lachlan.hunt@lachy.id.au>, public-html@w3.org, wai-xtech@w3.org

Jason White wrote:
> On Sat, Jul 28, 2007 at 03:08:12PM +1000, Lachlan Hunt wrote:
>> I think you're over thinking the solution too much.  Does there really need 
>> to be an explicit association between the video and the link to it's 
>> textual alternative?  What problem would such an explicit association 
>> really solve?
> 
> It would allow user agents to download the alternative, or the video itself,
> according to a configuration option specified by the user, or by the user's
> assistive technology, while presenting only a single link to the user
> interface.

I don't understand that reason.  In particular, "while presenting only a 
single link to the user interface" doesn't make sense.  Where and how 
are you imagining the UA to present this single link?

As I see it, the UA is still going to render the whole page.  If a user 
configures their UA to not download videos by default, then it doesn't 
have to.  The user can then read the page, and when they reach the link 
to the alternative content, they can download it.

> It would allow testing tools to check that there is an alternative associated
> with the video. This is important for the purpose of verifying conformance to
> site-wide or organizational policies, WCAG specifications, etc.

There is no requirement for all accessibility features to be testable 
using automated accessibility testing.  Such a requirement would only 
place arbitrary restrictions upon the development of accessibility 
features, limited by the abilities of testing tools.  Accessibility 
features should be evaluated according to how well they benefit users, 
not how easily a tool can test for it.

> The explicit association would also open up the possibility of special 
> treatment, in the user interface, of links to alternative content, such as 
> aural highlighting or access keys provided by the user agent, without 
> leaving these to be implemented by the content author as an implicit 
> association would do.

Possibly, but that would need research to determine things like whether 
users actually want or need that feature, whether or not they would 
really use it if it were available, and whether UAs, especially 
assistive technology, could or would implement it.

BTW, there was a suggestion for <a rel="longdesc"> a while ago, which, 
when used within <figure> and <legend>, is a possible solution.

>> Look at any video on YouTube, for example.  There is no explicit 
>> association in the markup between the video and its metadata, such as the 
>> user who uploaded it, the description, tags, number of times it has been 
>> viewed or favourited, etc.  Yet the user is still able to determine that 
>> they are related to the video.
> 
> What the user can determine isn't the point. The point, rather, is to extend
> what the user agent/assistive technology can determine.

No, the user is the whole point.  If it can be conclusively shown that 
the user is somehow disadvantaged because their UA doesn't provide some 
special functionality, then we can look at addressing those problems for 
the user.  But simply assuming that the UA needs to do something special 
and then jumping to the conclusion that we need to provide for that 
doesn't help.

>> I think an implicit association that the user can determine based on the 
>> context is sufficient.  I didn't explicitly define "alongside" because it's 
>> not necessary.  The exact markup used would have to be determined on a case 
>> by case basis.  But, I guess, an appropriate definition for "alongside" 
>> would be something like: somewhere on the page where the user can clearly 
>> identify the purpose of the link and its relation to the video based on its 
>> context.
> 
> This is inadequate for the reasons outlined above.

Only one of the reasons you gave was a possibility, and even that's not 
yet conclusive.  Therefore you can't yet claim that implicit association 
is inadequate.  Likewise, I can't conclusively claim that it is, but 
that would still be my hypothesis.

I'd like to see some user testing of this issue, and some documentation 
of existing video sites and their accessibility features.  Are there any 
existing video sites that provide textual alternatives for videos?  If 
so, we can look at how they do it and, through user testing, evaluate 
how successful their approach is.

There doesn't appear to be much research for videos documented in the 
wiki.  It would be good to fill it out a bit.

http://esw.w3.org/topic/HTML/AddedElementVideo

-- 
Lachlan Hunt
http://lachy.id.au/
Received on Saturday, 28 July 2007 07:30:47 GMT

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