- From: James Graham <jg307@cam.ac.uk>
- Date: Thu, 06 Jan 2005 10:16:26 +0000
Matthew Thomas wrote: > > For perhaps 95 percent of the images on the Web, the most appropriate > alternate text is nothing at all. (In 2003 I did a survey of images > in Wikipedia articles, where images aren't even used for decoration, > and still found that alt="" would be the most sensible choice for 77 > percent of them.) So for that 95 percent, assuming that no alt is > alt="" would improve the user experience. > > Unfortunately, the other 5 percent would ruin the idea. When > screenreaders are wading through inaccessibly-written pages, > sometimes images are used for navigation (graphical menus, for > example), so the user needs an indication that an image is there > (whereupon they can guess its function by its URI). Assuming that all > these images had alt="" would make such pages completely unnavigable. Both this and the other point that Jim made (implied alt is hard to debug) strongly suggest that alt should be optional, not implied. The lack of an alt attribute would legitimize any inference about suitable alternative text that the web browser wanted to perform. Therefore it would remain best practice to explicitly declare alt="" where the image is purely decorative. I expect many web developers would favor this approach since the validator complaining about a lack of alt="" has been perceived as unnecessary nannying and so the requirement has widely been ignored. Making alt optional probably wouldn't damage accessibility as much as might be thought because a) bad alt text is at least as bad as missing alt text and b) there exist other tools that explicitly check documents for accessibility which could flag missing alt attributes.
Received on Thursday, 6 January 2005 02:16:26 UTC