- From: Charles McCathieNevile <charles@w3.org>
- Date: Mon, 3 May 1999 22:19:17 -0400 (EDT)
- To: Jan Richards <jan.richards@utoronto.ca>
- cc: "w3c-wai-au@w3.org" <w3c-wai-au@w3.org>
This looks pretty cool to me... Charles On Mon, 3 May 1999, Jan Richards wrote: >From the document: 2.3.1: [Priority 1] Prompt the author to provide alternative content (e.g., captions, descriptive video). 2.3.2: [Priority 1] Prompt the author for all missing structural information (e.g., in HTML LABEL, FIELDSET, OPTGROUP and LEGEND for form controls). 2.3.3: [Priority 2] Provide pre-written alternative content for all multimedia files packaged with the authoring tool. 2.3.4: [Priority 3] Provide a mechanism to manage alternative content for multimedia objects, which retains and offers for editing pre-written or previously linked alternative content. 2.3.5: [Priority 1] Do not insert automatically generated (e.g., the filename) or place-holder (e.g., "image") equivalent text, except in cases where human-authored text has been written for an object whose function is known with certainty. Jan's Alt-Text Registry Technique Proposal In checkpoint 2.3.4 a recommendation is made that mentions the provision of a "mechanism to manage alternative content". This checkpoint is prioritized as a level 3, meaning that in itself, it does not have a critical effect on an authoring tool's likelihood of producing accessible mark-up. However, several limited extensions to this alternative content mechanism (ACM) have the potential to simultaneously meet several higher priority checkpoints and dramatically improve the usability of an access aware authoring tool . In particular: 1. The ACM should maintain a list of associations between object file names and authored responses to prompts for alternative content (as per checkpoint 2.3.1 [Priority 1]). The alternative content may take the form of short strings (i.e. "alt"-text) or pointers to descriptive files (i.e. "longdesc", transcripts, etc.). Multiple associations for the same object for different languages or contexts should also be handled. 2. The ACM would offer the associated alternative content as a default whenever the appropriate associated object is selected for insertion. If no previous association is found the field should be left empty (i.e. no purely rule-generated alternative content should be used). Note: the term "default" implies that the alternative content is offered for the author's approval. The term does not imply that the default alternative content is automatically placed without the author's approval. Such automatic placement may only occur when in situations where the function of the object is known with certainty as per checkpoint 2.3.5 [Priority 1]. Such a situation might arise in the case of a "navigation bar builder" that places a navigation bar at the bottom of every page on a site. In this case, it would be appropriate to use the same "alt"-text automatically for every instance of a particular image (with the same target) on every page. 3. The alternative content mechanism should be closely integrated with the pre-written alternative content provided for all packaged multimedia files, as per checkpoint 2.3.3 [Priority 2]. This would allow the alternative content to be automatically retrieved whenever the author selected one of the packaged objects for insertion. An important benefit of the system would be the ease of adding a keyword search capability that would allow efficient location of multimedia based on their alternative content. -- Jan Richards jan.richards@utoronto.ca ATRC University of Toronto --Charles McCathieNevile mailto:charles@w3.org phone: +1 617 258 0992 http://www.w3.org/People/Charles W3C Web Accessibility Initiative http://www.w3.org/WAI MIT/LCS - 545 Technology sq., Cambridge MA, 02139, USA
Received on Monday, 3 May 1999 22:19:23 UTC