Re: handling fallback content for still images

On 7/5/07, Smylers <Smylers@stripey.com> wrote:

> > It is at the author's discretion which method is best, for example,
> > whether I should use alt="Portrait of George Washington" or alt=""
> > because there is a heading/caption (i.e. context) that already
> > clarifies this.
>
> That example you gave is not really at the author's discretion.  You
> state two different scenarios, each of which require different
> alternative text.  The difference in the alternatives is because of the
> differing scenarios, not on the author's whim; it would be incorrect for
> an author to use them the other way round.
>

There is apparently still confusion over what the value of @alt should be if
that text would be reduntant.  <span><img src="washington">A portrait of
George Washington by John Doe from 1788</span> is a good example.  My
opinion is that @alt should be blank or omitted (!) because it would be
redundant - a screen reader would repeat the text in a way that sounds
silly.  My point, though, it that since reasonable people on this list can
disagree about @alt values, lay authors who are less technical and learning
HTML are hopelessly doomed to continue misusing and misunderstanding @alt.
figure/legend helps with this.  It must be made absolutely clear what markup
should be used for all cases of still images:
1. images that are purely decorative and do not represent text
-- <p><img src="random-stock-rose-photo"> A paragraph about the care of
roses...</p>
2. images that represent text in a way that completely replacing the image
with text does not change the meaning of the doucument
-- <a href="feed.rss">Subscribe to my <img src="rss.png" alt="RSS"> feed
3. images that are part of a document that need fall back text that
describes the image
-- the portrait of George Washington without accompanying text
4. images that are part of a document that are accompanies by text that
describes the image
-- the portrait of George Washington with accompanying text

2. is perfectly clear and is satisfied by <img alt>.  In fact, I think @alt
was only ever invented to satisfy 2. 1, 3, and 4 need to be specified in a
way that isn't open to debatable interpretation and is perfectly clear to
budding authors.

-- 
Jon Barnett