W3C home > Mailing lists > Public > public-html@w3.org > August 2015

Re: aria-describedat

From: James Craig <jcraig@apple.com>
Date: Thu, 6 Aug 2015 02:13:04 -0700
Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, Janina Sajka <janina@rednote.net>, PF <public-pfwg@w3.org>, SVG WG <public-svg-wg@w3.org>, W3C PF - DPUB Joint Task Force <public-dpub-aria@w3.org>, Michael Cooper <cooper@w3.org>, Judy Brewer <jbrewer@w3.org>, Markus Gylling <markus.gylling@gmail.com>, public-digipub-ig@w3.org, HTMLWG WG <public-html@w3.org>, Ted O'Connor <eoconnor@apple.com>, "David (Standards) Singer" <singer@apple.com>, Leonie Watson <lwatson@paciellogroup.com>, Steve Faulkner <faulkner.steve@gmail.com>
Message-Id: <57ED3FBE-5483-4984-979E-2E096EABEE00@apple.com>
To: George Kerscher <kerscher@montana.com>
Thanks for taking the time to write this up, George. 

I apologize that I do not have sufficient time for in-depth point-by-point rebuttals, and it is unlikely that I'll be able to attend the ARIA call next week due to a standing conflict. In lieu of my attendance, I would like to point out a few things the DPUB and WAI groups should consider.

1. Longdesc received formal objections from Apple and Mozilla, the developers of the most accessible browsers on most major platforms, and neither vendor took the decision to object lightly. Regardless of TBL's final decision to release longdesc, the points made in Ted O'Connor's #longobjection™ are still relevant to both @longdesc and @aria-describedat. 

    Formal Objection to advancing the HTML Image Description document
    https://lists.w3.org/Archives/Public/public-html-admin/2014Aug/0028.html  

2. In additional to the technical objections, the @longdesc and @aria-describedat attributes rely on a "separate but equal" design philosophy that we in the WebKit and Apple Accessibility Engineering teams consider to be Harmful for Accessibility. The specific points have been made ad infinitum, so I won't mention them again in this thread. 

3. I personally believe all of your points and examples below are sufficiently addressed by one or more of the following approaches.

   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 
   - Standard linking (<a href>)

I hope you'll come to the conclusion that @aria-describedat is unnecessary (even harmful), but can agree to disagree if we are at an impasse.

Cheers,
James Craig


PS. No response is necessary. Good luck with your work and the conference call next week. 


> On Jul 13, 2015, at 7:14 AM, George Kerscher <kerscher@montana.com> wrote:
> 
> Dear Rich and PF WG
>  
> Copying the DPub working group.
>  
> Below is the reply from the DPub working group you requested. We also have three attached images for illustration.
>  
> We look forward to a time in August where we could gather on a call.
>  
> Best
> George on behalf of the DPub Accessibility WG.
>  
> Begin message:
>  
> The Digital Publishing Interest Group asserts that the describedat ARIA property  genuine utility to the publishing industry. The myriad advantages of the attribute to the industry include:
> 
> 1. Showing the user an extended enhancement without losing current context.

Both the <details> element and <svg> alternatives provide this functionality.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 


> ·         Not offered by linking in HTML in a standard way.
> ·         Context is necessary for accessibility. This is especially important for anybody using a screen reader, or for any user with cognitive impairments. However, since both magnification use and mouse-less keyboard-less browsing can increase the difficulty of navigating, providing easy links to context can be very important.
> ·         Publishing use case: An article in Example Magazine contains multiple complex infographics that need to be described with watermarks/breadcrumbs guaranteeing the reader will always return to the current context.
> 
> 2. Offering 3D printer models as enhanced alternatives to viewing/printing for complex objects, such as a rotating visualization or a relief map.

Both the <details> element and <svg> alternatives provide this functionality.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 

> ·         Not offered by describedby, alt, longdesc. linking in HTML can't wrap complex dynamic objects, or objects which are already links.
> ·         3D printing models of 3D visualizations will be a game changer for blind/VI users of digital publications.
> ·         Publishing use case: An art history textbook with 3D printing instructions for Bernini’s David
> 
> 3. Providing structured markup in an extended enhancement.

Both the <details> element and <svg> alternatives provide this functionality.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 

> ·         Not offered by describedby or alt.
> ·         Structured markup is vital for accessibility. A screen reader user who does not have access to structure cannot navigate to the items in the list, cannot navigate via heading, and cannot have a screen reader voice appropriately change language according to language tag markup. Without structured markup a screen reader user cannot easily skim or skip around the sections of a lengthy extension. 
> ·         Publishing use case: a linguistics textbook with complex data visualizations needing rich description, including bulleted lists and marked up multi-language sections. (See attached images for examples.)
> 
> 4. Providing an extended enhancement to any element, even one thatis already a link

I'm not certain why you'd need a long desc for a link, but both <details> and <svg> can be used generally. They do not need to be associated with images.

> ·         Not offered in all cases with alt, longdesc, linking in HTML.
> ·         Extended enhancements need to be available for all page items for accessibility. Many images or complex visualizations on the web are already links as part of site design. Those need to be available to blind/VI users just as much as unlinked images.
> ·         Publishing use case: a historical map in a political science reference manual, with Baltic States clearly marked on the historical image links to a higher-definition map.
> 
> 5. Providing an extended enhancement to any element, including a dynamic one.

Both the <details> element and vector-based <svg> alternative provide this functionality.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/

> ·         Not offered in all cases with alt, longdesc, linking in HTML.
> ·         Extended enhancements need to be available for all items for accessibility. Many images or complex visualizations on the web are rich dynamic applications which cannot be made into links. Those need to be available to blind/VI users just as much as simple images.
> ·         Publishing use case: a required reading quiz at a chapter end with a manipulatable, dynamic timelapse overlay.
> 
> 6. Offering a large number of very lengthy enhancements in a single page without bloating the size and complexity of the source page

Standard linking and server-side content negotiation provide this functionality.

That said, I am skeptical that your long descriptions would result in significantly measurable size increase for a web page. 

"Complexity" is a more subjective term so you could have a valid point depending on the specific image examples and development stack, but please consider this. The goal of simplifying authoring complexity should never yield a result that provides a substandard experience to the end user.


> ·         Not offered by describedby, alt.
> ·         There are myriad reasons why this is an accessibility use case. First of all, accessibility has to become something publishers are willing to add to their digital publications. If adding many extended enhancements bloats the page such that it has a slow load time for the users who will not access the extended enhancements, publishers are less likely to add the enriched material. Moreover, slow load time can increase reading difficulties for users with cognitive  impairments, as well as for users with visual impairments, who are not necessarily informed of what is happening during page load.
> ·         Publishing use case: a picture book displaying a complex four-part story, in which details from one story interact with details from another.
> ·         Publishing use case: a biology textbook chapter with a very large number of cell images, each of which needs to be described with description of the cell components
> 
> 7. Providing access to extended enhancements in ways that don't conflict with visual design.
> ·         Not offered by linking in HTML.

I reject this hypothesis. Links can be styled to disappear completely and/or display only when focused. As such, they provide all the functionality of longdesc and describedat, but perform better in more browsers and with more assistive technology.

In addition, both the <details> element and <svg> alternatives provide this functionality and can be styled such that the design is not impacted.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 


> ·         Although visual designers and layout designers need to follow accessibility standards, ultimately visual design is often decided in such a way that negotiation is impossible, sometimes contractually and sometimes aesthetically. Putting a hyperlink after the item with the anchor text "enhanced explanation of table 1.1" relies on the ability to modify layout and visual representation. Exposing the enhancements via user agent functionality or adaptive technology doesn't have an influence on the visual design.
> ·         Publishing use case: a publisher receives the contract for creating an ebook of the original draft of Samuel Beckett's Waiting for Godot. The terms of Samuel Beckett's will specify that no words be visible on the page which were not written by Beckett himself, and the visual layout be as close to his original draft as is possible.
> 
> 8. Reusable, updateable and programmatically referenceable extended enhancements.

Both the <details> element and <svg> alternatives provide this functionality.
  
   - Figure with details element: http://cookiecrook.com/longdesc/details/
   - Accessible vector graphics in SVG: http://cookiecrook.com/longdesc/svg/
   - Raster graphics in an SVG Wrapper: (no example available) 


> ·         Not offered by describedby, alt
> ·         Publishers are most likely to rapidly implement accessibility practices that have a sustainable workflow.
> ·         Publishing use case: an online test manufacturer uses the same complex table in a whole series of online tests;  in the three different e-books they publish about practicing for the tests; and in the answer key provided to test scorers. They write a single extended enhancement and store it in a database along with the ID of the table. When the test is released, the describedat attribute is added referencing a link to the extended enhancement, which is made available online. After the tests have been released and pushed to test centers, the test manufacturer discovers an error in the complex table description. They update a single description.
> Sample Markup for  a subset of these use cases included at end.
> We acknowledge that concern has been raised over the inability to access online resources in an offline source document. However, we believe that concern is being adequately addressed by ongoing efforts in the Digital Publishing space to collapse the currently-sharp distinction between online and offline resources. EPUB+WEB <https://w3c.github.io/epubweb/> is the primary umbrella project collecting all the avenues of research in this space.
> Annotations may address some of these use case, but it is not yet a Recommendation, and accessibility needs to be further addressed in the Draft.
> The DPUB IG has open and active channels of communication with the BISG accessibility team, and is confident that the publishing industry is passionate about accessibility at this moment, and is very willing to attempt to implement standards formalized by the W3C and implemented in user agents. The use cases above are problems the publishing industry must solve in the near future, and it is looking to the W3C for help formulating solutions. In the last several months, there has been a whirlwind of activity around accessibility in the publishing community. Every industry organization (more than 30) has a task force dedicated to accessibility, to the point that several of us are working to consolidate efforts. This query comes at a time of heightened awareness in the publishing world, as several key actors are poised to act. Publishers are embracing the full suite of accessibility best practices, and describedat is a powerful tool. We will evangelize this as the best option, and they have shown they are poised to listen.
> Sample Markup:
> Example for Use Case 2.
> <img src="http://www.worldmapsonline.com/images/HS432.jpg" alt="Relief map of the United States" aria-describedat="/CAD_files/usmap.cad">
> Example for Use Case 5.
> On a Google maps time lapse view used in a dynamic textbook, eg:https://www.google.com/maps/@42.362753,-71.089829,3a,75y,213h,90t/data=!3m7!1e1!3m5!1s46xSQNv8yySyc1t9rJBaig!2e0!5s20121001T000000!7i13312!8i6656!6m1!1e1?hl=en
> <div jstcache="517" class="widget-timemachine-dropdown-container"
> aria-describedat="TimeMachineTextualEnhancement.html"> ... </div>
> Example for Use Case 6. Also works as an example for Use Case 3.
> File 1: black-and-white.html
> <img src="http://students.english.ilstu.edu/jmklass/images/black2.jpg"
> alt="David Macauley's Black and White, pages 5-6"
> aria-describedat="/foo/bw56.html">
> File 2: bw56.html
> <h1>David Macauley's Black and White, pages 5-6</h1>
> <!-- TOC here -->
> <h2>Story 1: Seeing Things</h2>
> <h3>Art Style</h3>
> ...
> <h3>Text</h3>
> ...
> <h3>Art Style</h3>
> ...
> <h3>Image description</h3>
> ...
> <!-- repeat for stories 2-4 -->
> <h2>Inter-story Interaction</h2>
> <!-- Describe the interaction between stories 2 and 4 as shown in the image -->
>  
>  
>  
> From: Richard Schwerdtfeger [mailto:schwer@us.ibm.com] 
> Sent: Wednesday, June 17, 2015 6:54 AM
> To: George Kerscher; janina@rednote.net
> Cc: PF; SVG WG; public-dpub-aria@w3.org; cooper@w3.org; jbrewer@w3.org; Markus Gylling
> Subject: aria-describedat
>  
> George, Janina, 
> 
> As you know, we put aria-describedat in the ARIA 1.1 spec., however the caviat for it staying was that we see adequate support from a number of key publishers that they would commit to using it if we actually kept it in the specification. This was months ago. Janina had promised me that after I came back from vacation that we would see something either way from publishers. I have been back two weeks now and there has been no movement. 
> 
> At this point I am trying to lock down the ARIA 1.1 specification so that we can work on ARIA 2.0 which will address critical features such as extensibility and greater support for web applications. Also, the group has additional modules in development for digital publishing and graphics that are coming in parallel that are taxing people's time. 
> 
> So, allowing for possible mis-communications between PF and the publishers I am going to give to mid-August to see a strong response from publishers. If we do not see it I am going to propose that aria-describedat be removed from the ARIA 1.1 specification. 
> 
> Rich
>  
> 
> 
> Rich Schwerdtfeger
> 
> 
Received on Thursday, 6 August 2015 09:14:04 UTC

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