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Re: Call for Review: HTML5 Image Description Extension (longdesc) Last Call

From: Charles McCathie Nevile <chaals@yandex-team.ru>
Date: Wed, 17 Jul 2013 09:30:34 -0700
To: public-html-a11y@w3.org, "James Craig" <jcraig@apple.com>
Cc: "Jeanne Spellman" <jeanne@w3.org>, "Richards, Jan" <jrichards@ocadu.ca>
Message-ID: <op.w0cxw8j9y3oazb@chaals.local>
Hi James,

On Tue, 16 Jul 2013 10:40:18 -0700, James Craig <jcraig@apple.com> wrote:

> I have an additional suggestion that I believe would help the acceptance  
> of this document within the general working group. Add an informative  
> section detailing several of the many cases where it is inappropriate to  
> use @longdesc. For example…

I think some of these are misplacing the cause of the problem they attempt  
to solve:

> 1. @longdesc is inappropriate when an EPUB footnote is sufficient.

Can you explain why it is "inappropriate" in terms of the problem that  
using it causes?

In cases where apple users are targeted it is of course necessary to  
provide a fallback, since VoiceOver doesn't curently enable longdesc to be  
used, but that is not the same as causing harm by using the attribute.

> 2. @longdesc is inappropriate for Math. Use MathML instead.
> 3. @longdesc is inappropriate for SVG graphics. Make the SVG DOM  
> accessible instead.
> 4. @longdesc is inappropriate for graphics of tabular data. Use an  
> accessible table instead.

In all of these cases, you appear to be blaming the use of longdesc as a  
repair strategy for an inappropriate design choice to which longdesc is  

Using images for mathematical content, or tabular data, is a known  
accessibility fail. But in a case where the image is there, using longdesc  
to mitigate the failure seems far better than simply throwing up your  
hands and saying "the world shooulda been different"...

In the case of SVG we currently have a disconnect between theory and  
reality. Although my text on SVG accessibility is (after more than a  
decade) pretty solid on how to make the DOM accessible, in practice I  
believe that is only useful for the relatively small proportion of users  
who have VoiceOver. I realise it is bigger in some markets, but the best  
figures I can get for Russia suggest that is under 5%. In this situation,  
while I strongly support the idea that the DOM should be accessible, it  
seems that a longdesc as a temporary repair strategy for windows users -  
i.e. the vast bulk of real people - is actually a very helpful thing to do.

> These should probably be added to the WCAG 2.0 Techniques documents as  
> well.

We certainly need to look at the WCAG 2 techniques document, and upgrading  



> On Jul 16, 2013, at 9:32 AM, "Richards, Jan" <jrichards@ocadu.ca> wrote:
>> Nice work. I just have a few suggestions:
>> 1. Double-check the consistency of capitalization in "Requirements for  
>> an Image Description functionality". Some items have each word  
>> capitalized while others do not and then some have different  
>> capitalization in different places ("Simple Return" ). My preference is  
>> usually for less capitalization.
>> 2. re: the section referencing ATAG 2.0 that is marked with " ISSUE:  
>> This doesn't seem a great reference - is there anything better? This is  
>> tracked in bug 21501 and its dependent bugs. Unless a proposal for  
>> improvement is made and accepted this bug will simply be closed after  
>> Last Call."
>> Right now it points to:
>> " Implementing PRINCIPLE B.3: Authors must be supported in improving  
>> the accessibility of existing content "  
>> (http://www.w3.org/TR/ATAG20-TECHS/#principle_b3)
>> ...which is probably too general.
>> There are other anchors in "Implementing ATAG 2.0" that provide more  
>> specific information. This is probably the most specific:
>> http://www.w3.org/TR/ATAG20-TECHS/#prompt-long-description
>> Also, these two sections that explain how checking and repair can range  
>> from manual to fully-automated also include relevant descriptive text  
>> examples: http://www.w3.org/TR/ATAG20-TECHS/#checking-types
>> http://www.w3.org/TR/ATAG20-TECHS/#repair-types
>> Cheers,
>> Jan
>> T 416 977 6000 x3957
>> F 416 977 9844
>> E jrichards@ocadu.ca
>>> -----Original Message-----
>>> From: Mark Sadecki [mailto:mark@w3.org]
>>> Sent: July-16-13 11:45 AM
>>> To: w3c-wai-ig@w3.org
>>> Cc: Steve Faulkner; Charles McCathie Nevile; Janina Sajka
>>> Subject: Call for Review: HTML5 Image Description Extension (longdesc)  
>>> Last
>>> Call
>>> Dear WAI Interest Group Participants,
>>> The HTML Accessibility Task Force [1], which is a joint task force of  
>>> the
>>> Protocols and Formats Working Group (PFWG) and the HTML Working Group
>>> (HTML WG), invites your comments on the Last Call Working Draft of the
>>> HTML5 Image Description Extension at:
>>>      http://www.w3.org/TR/html-longdesc
>>> This specification ("HTML-longdesc") enables web authors to provide  
>>> longer
>>> textual descriptions for complex images. HTML-longdesc is an extension
>>> specification that is part of the HTML5 family of specifications [2],  
>>> which
>>> enables it to evolve independently and be finalized more rapidly. HTML-
>>> longdesc is part of W3C's work to ensure that the Open Web Platform  
>>> [3] is
>>> accessible to people with disabilities [4].
>>> This draft is based on feedback received on two previous Working  
>>> Drafts and
>>> addresses a number of bugs that were raised and resolved. The HTML
>>> Accessibility Task Force believes this draft is stable and  
>>> implementable, and
>>> looks forward to progressing to the next stages in completing the HTML5
>>> Image Description Extension. "Last Call" and next stages are described  
>>> in How
>>> WAI Develops Accessibility Guidelines through the W3C Process:  
>>> Milestones
>>> and Opportunities to Contribute at:
>>> <http://www.w3.org/WAI/intro/w3c-process>
>>> A list of changes since the previous publication and specific  
>>> questions for
>>> review are available from the Change History section at:
>>>      http://www.w3.org/TR/2013/WD-html-longdesc-
>>> 20130716/Overview.html#changes
>>> Please send any comments on this Draft to the publicly-archived HTML
>>> Accessibility Task Force mailing list:
>>>      public-html-a11y@w3.org
>>>      *by 16 September 2013*
>>> About the URI:
>>> The first URI above goes to the latest version of the specification.  
>>> The
>>> "dated" version of this Working Draft is:
>>>      http://www.w3.org/TR/2013/WD-html-longdesc-20130716/
>>> The difference between these URIs is explained in Referencing and  
>>> Linking
>>> to WAI Guidelines and Technical Documents at:
>>>      http://www.w3.org/WAI/intro/linking
>>> Please let us know if you have any questions. Feel free to circulate  
>>> this
>>> message to other lists; please avoid cross-postings where possible.
>>> Thank you in advance for your comments.
>>> Regards,
>>> ~ Mark Sadecki, W3C Staff Contact for the HTML Accessibility Task Force
>>> HTML Accessibility Task Force Co-Facilitators: Steve Faulkner, Charles
>>> McCathie-Neville, Janina Sajka WAI Outreach Coordinator: Shawn Henry  
>>> WAI
>>> Domain Leader: Judy Brewer
>>> [1] Task Force <http://www.w3.org/WAI/PF/html-accessibility-tf.html>
>>> [2] Blog about extension specifications
>>> <http://www.w3.org/QA/2012/09/getting_html5_to_recommendatio>
>>> [3] Open Web Platform standards <http://www.w3.org/standards/> [4]
>>> Accessibility - W3C  
>>> <http://www.w3.org/standards/webdesign/accessibility>
>>> --
>>> Mark Sadecki
>>> Web Accessibility Engineer
>>> World Wide Web Consortium, Web Accessibility Initiative
>>> Telephone: +1.617.715.4017
>>> Email: mark@w3.org
>>> Web: http://w3.org/People/mark

Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
       chaals@yandex-team.ru         Find more at http://yandex.com
Received on Wednesday, 17 July 2013 08:31:10 UTC

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