RE: Empty vs no alt attribute (was Re: Baby Steps or Backwards Steps?)

Chris, 
   What about the instance of images in place purely for decoration?  If
an image holds no value in to the document in a non-visual context then
surely supplying an alternative is degrading the non-visual experience.
In regards to your suggestion of calling out "Author did not provide
alternative text", this would also degrade user experience would it not?
I can imagine going through a page and having that read out 20 times to
be far more annoying than having no alternative read.
 
Richard.

________________________________

From: public-html-request@w3.org [mailto:public-html-request@w3.org] On
Behalf Of Chris Blouch
Sent: 21 August 2007 15:49
To: joshue.oconnor@cfit.ie
Cc: Sander Tekelenburg; HTMLWG; wai-xtech@w3.org; Don Evans
Subject: Re: Empty vs no alt attribute (was Re: Baby Steps or Backwards
Steps?)


Two aspects that seem to be overlooked in the discussion.

1. While there is an expectation that alt should be used for alternative
equivalent text descriptions, in practice many browsers also use it for
their popup "tooltips". This had lead some site authors to assume the
purpose was more supplemental rather than alternative so they have
stored additional meta data rather than real descriptions. Hence we see
sites putting up "200x100 GIF Image July 12, 2007" as their alt text
instead of a real content description. While this is incorrect use of
the attribute, it is hardly a surprising assumption based on browser
behavior.

2. The problem with allowing images without alt attributes in some cases
is that this essentially writes a loop hole into the standard. This then
puts the burden on the standard to sufficiently constrict this loop hole
such that it can't be abused. Hardening any loophole in a set of rules
is difficult at best. We need look no further than laws of governing
bodies for examples. As for the presence of alt tags being provisionally
required, it would seem to be simpler to require them in all cases and
then move debate to defining the presence and quality of the
descriptions themselves, whether good, lousy or absent. At least this
makes for any easy minimum test, a test which many tools already
implement. Loopholes for poor or missing alt text would be a more
fertile ground for work in the standard, but still a quagmire.

I suggest that missing alt text should be called out in a manner that
points out the author's mistake (either directly or via their tools).
Something like "Author did not provide alternative text" or whatever
wordsmithing is desired. This provides a means for discoverability by
others to feed back to the source that something is wrong. If Grandma
sees no tool tip or one that says just "undefined" she will ignore it.
If she sees a message pointing fingers at my failure to do something
right I might actually get an email from her. In other words, while the
tooltip and non-descriptive errors for alt text may not directly enable
users who need alternative content, it can enable other users to seek
out resolution to a problem that was previously invisible to many.

CB

joshue.oconnor@cfit.ie wrote: 

	Sander Tekelenburg wrote:
	  

		I cannot imagine how alt="unknown" could be useful to
anyone. 
		    

	
	I am also at a loss to understand how this is useful. Is it
expected
	that screen readers would read output "unknown" when they came
across
	and image that used the attribute in this way?
	
	Josh