Re: fear of "invisible metadata"

On Jun 21, 2007, at 9:31 AM, Laura Carlson wrote:

>
> An alt attribute is not a label or description for the image. This is
> not an immediately obvious distinction. In fact, it might seem natural
> to assume that alternate text is a label or a description. It is not.
> The words used should be a text equivalent and convey the same
> information/serve the same purpose as the image. The aim is to provide
> the same functional information that the visual user sees. The alt
> text should be a "stand in" if you will if the image is missing. The
> test is, when you replace the image with the text would everyone do
> the same thing/receive the same information as best as possible?

This is exactly why I think alt is sometimes not appropriate. In some  
cases, such as photo sites like flickr, there's no way to have  
alternate text that serves the same purpose of the image, since the  
whole point of such web pages is to show photos. Sadly we can't  
provide the same functional information to a non-sighted user, since  
the information in this case is inherently visual. Much the same as  
you can't provide a good alternative for an embedded piece of  
instrumental music to a deaf user.

> Before CSS, an empty alt (i.e. alt="") was the best mechanism we had
> to use for images which played only a decorative (eye candy) role in a
> page. Eye candy are things that serve no purpose other than to make a
> site visually appealing/attractive and (in many cases) satisfy the
> marketing departments. There is no content value (though there may be
> value to a sighted user).

I think the case that's not covered is content that is semantically  
meaningful, not "just eye candy", but where at best you can provide a  
description (possibly already in the document), not an alternative.  
Once again I cite <http://flickr.com/photos/othermaciej/>. The images  
in there are all very much meaningful (they are the point of the  
page) but it's hard to imagine useful alternative text.

Regards,
Maciej

Received on Thursday, 21 June 2007 21:43:20 UTC