While checking out a US gov’t document online, I ran across an alternate text approach I hadn’t seen before. Several pages in this seven-page booklet had moderate complexity, i.e., some graphic elements, text wrapping around a few photos, etc. Rather than including alternate text for individual figures and other graphics, someone had tagged the entire page as a figure and copied all of the paragraph and heading content, along with descriptions of the graphics, into the alternate text field.
I ran the Acrobat 9 Pro accessibility checker, and it didn’t find any problems with these pages. I saved the document as an accessible text file, and everything was there in the proper order. I listened to it with Read Out Loud – worked just fine.
My questions:
1) Is this a kosher way to use alternate text for Section 508 compliance? (Back in my html days I was instructed to keep alt tags short, but maybe that’s not applicable here.)
2) What are the drawbacks of this approach? Reflow would seem to be one of them.
Just me nattering, but, it appears to be "quick fix" to permit providing a "compliant" PDF in the 11th hour.
Regarding Acrobat's Full Checker -
A frequent comment, made by Duff Johnson, is that the Acrobat Full Checker options do not establish that a PDF is "accessible".
The disclaimer that is present in the Full Checker dialog confirms this.
Regardless, the options available are valuable for tightening the focus on what is "ok" and what remains to be done.
So, appropriate content authoring, Full Checker, read order, reflow, save as to accessible text file, visual review of the PDF's pages with TORU, and other checks become necessary to be on target with an accessible PDF.
Ok, the document is "compliant" and, from your description of the detailed information placed in the alternate text, it would seem to usable; thus accessible.
The litmus test would be an end-user using AT of their choice/need obtaining unambiguous understanding of the content (with no unwarrented speed humps along the way). If yes, then the PDF would be "good to go".
Thing is, the PDF's "set up" for accessiblility called for a somewhat non-trival pre-staging of content that had to then be placed into the alternate text field.
Generally, the ability to do this with success relies on someone's knowledge/ability & is lost when the individual moves on.
"Tribal knowledge" sort of thing.
Next time the authoring file changes, all the "input" info for the alternate text must be edited, checked, and placed anew into the PDF.
Long term, this approach tends to be more resource intensive (and, decidedly relies on the "tribe's shaman" being available).
Better to "get it right" in the authoring file which minimizes post-processing activities on the PDF ( a "measure twice, cut once approach).
Dave
Be well...