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Re: agenda+ Review of the Longdesc spec

From: Greg Lowney <gcl-0039@access-research.org>
Date: Wed, 22 Jan 2014 21:49:40 -0800
Message-ID: <52E0AD74.6000106@access-research.org>
To: WAI-UA list <w3c-wai-ua@w3.org>
Here are my comments on the HTML5 Image Description Extension (longdesc) (https://dvcs.w3.org/hg/html-proposals/raw-file/default/longdesc1/longdesc.html).

*1. Use Case keywords seem random:* In the section on Use Cases, the Requires and Helped By keywords (which link to appropriate entries in "Requirements for an Image Description Functionality") are a nice touch. However, I can't understand the choices made as to which keywords are listed for each use case. For example, why would Discountability be important for "Identifying a well-known image", but not for "Describing a complex diagram", or why would Simple Return be useful for the latter but not the former?

*2. Contrast with ARIA DescribedBy:* The use case "Referring to an existing description" sounds like exactly what ARIA DescribedBy is used for, so it might be good to clarify why longdesc is also needed, and whether you're recommending one or both be used.

*3. Other image types:* I don't understand the decision to allow the new longdesc to apply only to img elements, as it seems to be just as appropriate for things like groups of images (which may make up one whole image as far as the user is concerned), svg elements, objects, and even tables or arrangements of colored divs. Can you please explain the rationale for not allowing it on other elements?

*4. Provide UI guidance:* The document should really provide some guidance or examples of how user agents could implement linked images with longdesc. Section 3.0.3 says "If the longdesc value is valid, User agents must make the link available to all users through the regular user interface(s)." but that's ambiguous as to whether it means "through the user agent's own UI (rather than relying on assistive technology)" or "through the user agent's normal clicks and keystrokes for activating links". It's clear that the user agent can't simply provide a single standard hyperlink when the img is inside an anchor and also contains a longdesc unless that pops up a choice of jumps, but it could instead apprend a separate hyperlink to the longdesc, or it could provide a separate command on the link's context menu and/or on a menu bar menu when the element has focus, etc. Of course, any guidance should be suggestions, rather than prescriptive, as we don't want to prevent user agent 
developers from providing new, innovative UI or UI that's appropriate for their product and its platform.

*5. Delimit blocks in the document:* As a purely editorial/formatting issue, the document should not convey information by graphical formatting alone. The problem is that the blocks starting with "This section is informative" are indented and have a differently colored background, but there is nothing textual to denote where the block ends. Thus, if one is reading or listening to the text that reads "This section is informative Best practices for full descriptions of images are beyond the scope of this document, but there are many resources available. Authors should not rely solely on longdesc where standards exist to provide direct, structured access." it is not immediately clear whether the third sentence is inside or outside the informative block. The reader may be able to infer it out from context in some cases, but that should not be required nor relied upon.

*6. Web page contains insecure content:* FYI, when loading the page https://www.w3.org/WAI/EO/wiki/UAAG_review, my copy of Firefox 26.0 generates a warning saying "Firefox has blocked content that isn't secure. Most websites will still work properly even when this content is blocked." It links to the following page for details: https://support.mozilla.org/en-US/kb/how-does-content-isnt-secure-affect-my-safety.


-------- Original Message --------
Subject: agenda+ Review of the Longdesc spec
From: Jeanne Spellman <jeanne@w3.org>
To: UAWG <w3c-wai-ua@w3.org>, Jim Allan <jimallan@tsbvi.edu>, Kelly Ford <Kelly.Ford@microsoft.com>
Date: 1/22/2014 11:57 AM
> UAWG has been asked to do a review of the Longdesc within the next week.  They are ready to move to Proposed Recommendation (apparently, they have already done their testing, so they are skipping Candidate Recommendation).
> https://dvcs.w3.org/hg/html-proposals/raw-file/default/longdesc1/longdesc.html
> Please take some time before the meeting on Thursday to review it and make any notes we should discuss. It would be helpful to send your notes to the mailing list.
> jeanne
Received on Thursday, 23 January 2014 05:50:03 UTC

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