Edit comment LC-2851 for Accessibility Guidelines Working Group

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Comment LC-2851
Commenter: Laura Carlson <laura.lee.carlson@gmail.com>

Resolution status:

Thank you very much for agreeing to provide on-page longdesc syntax in order to help people understand how it works and what limitations exist. I agree with the direction you are taking but suggest helping authors to overcome any limitations by incorporating a end-point solution into H45's verbiage and example as well as pointing out the advantages of using a separate resource by changing:

H45: http://www.w3.org/TR/WCAG-TECHS/H45.html

Authors can provide a description for an image by including text in a separate resource or within the text of the page containing the image.
<ins>An advantage of using a separate resource for the description is that it is easily reusable for multiple instances of the same image, it does not add on-page visual clutter to the original document, and the description's end-point is self evident.</ins> An advantage of providing the description within the same page as the image is that all users can access the description. A limitation of <del>this</del><ins>the on-page</del> method, as well as in providing multiple descriptions on a single separate page, is that current implementations supporting longdesc <del>read all text on the page that follows the start of the long description</del><ins>do not identify the long description's end-point</ins>. <del>As a result, an end user may hear the long description and all content on the page following it, without knowing where the long description is intended to end unless authors provide text to help users identify the end-point of the description.</del><ins>Authors can solve this by providing a well-formed description, which identifies the where the description ends.</ins>

[On-page Example]
(suggested change is in addition of H3 and P inside the div#desc)

<img longdesc="thispage.html#desc"
alt="Line graph of the number of subscribers"
<div id="desc">
<h3>Long Description: Line graph of the number of subscribers</h3>
<!-- Full Description of Graph -->
<p>Long description ends.</p>

Laura also suggests various resources for inclusion, below:

Related Resources:

Description Available in a Separate Document Provides Efficiency http://www.d.umn.edu/~lcarlson/research/constriants/separate-doc.html

Forced Visual Encumbrance Adds Visual Clutter http://www.d.umn.edu/~lcarlson/research/constriants/visual-encumbrance.html

In addition WCAG WG may want to consider demonstrating to authors how to provide an actual long description by replacing the comment: <!-- Full Description of Graph --> with markup.

For example:

More longdesc Examples:



(space separated ids)
(Please make sure the resolution is adapted for public consumption)

Developed and maintained by Dominique Hazaël-Massieux (dom@w3.org).
$Id: 2851.html,v 1.1 2017/08/11 06:40:02 dom Exp $
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