Re: alt and authoring practices

On May 4, 2008, at 11:19 , Henri Sivonen wrote:

> When a user of Nvu doesn't provide a textual alternative to Nvu, is  
> the result better or worse for the user experience of the page  
> reader than Nvu omitting alt and letting UAs indicate the presence  
> of an image in a self-consistent UA-specific way?


What I'm trying to get at is this:

Alt has three states:
1) Not available.
2) Specific text available.
3) Conceal the presence of image from non-graphical rendering.

A single text field without an accompanying checkbox can only handle  
two states: #2 and either of #1 and #3.

I think it's reasonable for authoring tools aimed at 'average users'  
to only have a single text field, but I think in that case the overall  
outcome is better if leaving the text field empty maps to case #1 (no  
alt) than to case #3 (alt="").

Also, I think some products only supporting two of the three states  
shouldn't preclude the spec and other products from supporting the  
three states.

-- 
Henri Sivonen
hsivonen@iki.fi
http://hsivonen.iki.fi/