- From: <bugzilla@jessica.w3.org>
- Date: Wed, 10 Aug 2011 03:17:47 +0000
- To: public-html@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=13727 Summary: regarding "phrase or paragraph with an alternative graphical representation" Product: HTML WG Version: unspecified Platform: PC URL: http://www.w3.org/mid/B6CB855C5769484F862F4FB2CCFA50F4 02D545A7@VHAISHMSGJ2.vha.med.va.gov OS/Version: All Status: NEW Severity: normal Priority: P2 Component: LC1 HTML5 spec (editor: Ian Hickson) AssignedTo: ian@hixie.ch ReportedBy: mike@w3.org QAContact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-wg-issue-tracking@w3.org, public-html@w3.org +++ This bug was initially created as a clone of Bug #13726 +++ http://www.w3.org/mid/B6CB855C5769484F862F4FB2CCFA50F402D545A7@VHAISHMSGJ2.vha.med.va.gov A phrase or paragraph with an alternative graphical representation: charts, diagrams, graphs, maps, illustrations This section is clearly meant to fill the role of the longdesc attribute. Unfortunately, the reasoning used is flawed. It assumes several things: 1. That all users require the same level of description for complex information at all times; 2. That the alt attribute is adequate to the task of conveying textual descriptions of graphical information. At the VHA, we encounter graphical information in the form of screen-captures of what would otherwise be tabular data, or charts with complex interrelationships of information. If the suggested implementation here were to be used, a user (such as a screen reader user) could encounter something like: <img src="screenshot.jpg" alt="Table with five rows and five columns listing types of conditions and their severity. The first cell (column 1, row 1) is empty. Column 2, Row 1, says Pulmonary; Column 3, Row 1 says Circulatory; Column 4, Row 1 says Muscular; Column 5, Row 1 says Neurological. Column 1, Row 2 says, Minor Concerns ... Column 5, Row 5 says coma"> Not only would this be tedious to listen to for anyone who just needed to know that the image was a screenshot with lists of different types of ailments, it would not allow them to explore the layout of the table in a 2-dimensional way, to understand the relationship of the tabular data. The argument could be made that this information should have been provided in tabular form anyway, without the graphic, except that the purpose of the graphic is not just to convey the data itself, but to show how it would be presented in a particular computer application for a user to select from. It would be much more useful to provide multi-layered description (such as could be available with a modified and updated longdesc attribute) so that the image would be presented as: <img src="screenshot.jpg" alt="screenshot of ailment selection screen" longdesc="LinkToTableInformationForThoseWhoWantIt">. This would also be true of complex charts describing multiple factors that interact, or in less formal items like clothing catalogs where both an alt="short-sleeved shirt" could be supplemented with a long-description that gives details to only those who need more description. Those who were not looking for ANY type of short-sleeved shirt would not have to deal with the description of the fabric and color, etc. However, if a new form of long description is implemented, the description of how to utilize it should be made much clearer, and user-agents should be able to make that information available to any user who wants it; not just screen-reader users. In some ways, it would seem that adapting the details element to this purpose could work nicely (perhaps also becoming an attribute of img, or there should be a way of adapting it to an "additional information about images" role). Coming up with a details-as-attribute or being able to apply a details element to an image could alleviate one of the problems with longdesc - far too few people knew what it was meant for. Since the details element is described as being something that is used to provide further information on text, being able to apply it or something like it to img would basically do the same thing - provide a clickable element that indicates that there is more information available. [split out from bug 13590] -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
Received on Wednesday, 10 August 2011 03:17:48 UTC