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Re: Response to: ChangeProposals/DeprecateLongdesc

From: Janina Sajka <janina@rednote.net>
Date: Tue, 23 Aug 2011 18:31:51 -0400
To: public-html-a11y@w3.org
Message-ID: <20110823223151.GE8391@sonata.rednote.net>
Silvia Pfeiffer writes:
> The problem of aria-describedby automatically starting to read out the
> description is not as a big a problem as you make it out to be. Every
> screen reader has a key that stops the screen reader from continuing
> to read what it is currently reading ...

And then what? Are we to  abandon reading anything else on the page? If
we resume, where do we resume? Right in the middle of that
long-description that wasn't so interesting and caused us to stop speech
in the first instance?

No, Silvia, it won't work that way. This is a problem. It's a problem
that has long been resolved, but one that HTML5 seems to want to force
on us again.

The historic resolution is that we have two mechanisms:

1.)	A short stand-in for the graphic/figure which serves to identify
it. This is called the alt attribute and is automatically read.

2.)	The long text alternative description which provides more
detailed information about the image. In HTML4, and in our TF consensud
proposal, it's called longdesc, and it's read only when the user
requests it be read.

Asking for an element/ or attribute to behave both ways, sometimes auto
read, sometimes read only upon request, is nonsense because there's
simply no reliable way to support both behaviors in the same mechanism.
The one subverts the functionality of the other. You can't have it both
ways in the same mechanism.

Please note we defined this, howbeit tersly, two years ago in:
WAI CG Consensus Recommendations on Text alternatives in HTML 5

PS: What I think you're on the verge of re-inventing is something we
called "Escapable Structures" in DAISY. When one begins to read a long
"subroutine" of the primary text, perhaps a complex table, one might
decide to stop reading that structure and resume reading the primary
content, ergo "Escapable Structures."



Janina Sajka,	Phone:	+1.443.300.2200

Chair, Open Accessibility	janina@a11y.org	
Linux Foundation		http://a11y.org

Chair, Protocols & Formats
Web Accessibility Initiative	http://www.w3.org/wai/pf
World Wide Web Consortium (W3C)
Received on Tuesday, 23 August 2011 22:32:16 UTC

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