Re: [html4all] HTML5 Alternative Text, and Authoring Tools

On May 2, 2008, at 17:42 , Julian Reschke wrote:

> In doubt, the default should be not to change HTML4.


FWIW, I have a different view of what to do when in doubt:

When in doubt, do what doesn't cause harm.

I think experience (yes, not written down quantitatively) with HTML4  
validation shows that casting an *accessibility* requirement into a  
simplistic presence/absence *syntax* requirement does both good  
(reminds some people to provide useful alt who somehow wouldn't  
otherwise) and harm (induces people to pollute non-graphical  
presentation with duplicate data, useless data like "image" or make  
the context less understandable by concealing the presence of images).

I believe the current design in HTML 5 and Validator.nu's Image Report  
feature will pretty much remove the bad effects of requiring alt for  
validation. Thus, if we consider some kind of indifferent zero level  
of aggregate goodness/badness, it removes the negative side, so other  
things can only leave the aggregate positive or to the zero level.

In all likelihood, it will also lop off *some* of the good effects.  
Still, it seems totally implausible that people who provide alt  
because they care about accessibility would suddenly stop if it  
weren't a machine-checkable *syntax* requirement. Hence, it seems  
plausible that the aggregate effect will remain on the positive side.

Taking a course of action that has both good and bad effects on top of  
a net-positive aggregate baseline means seeking to do some good while  
accepting collateral damage of the bad side. I think a course of  
action with collateral damage should be based on data about the  
aggregate delta effect of the course of action remaining positive.

We don't have data about that, so defaulting to removing the negative  
side without knowing the magnitude of either makes sense.

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

Received on Saturday, 3 May 2008 09:38:04 UTC