Re: Guideline 1 in The evaluation techniques document

At 11:56 AM 6/24/99 +0300, Nir Dagan wrote:
>I realy do not understand the idea behind:
>
>Not allowed - NULL ALT value (ALT="")
>Allowed - ALT value of 1 or more spaces (ALT=" ")
>
>Both from a semantic/logical point of view and HTML specification 
>these are quite the same thing.

Not quite.  You are ignoring the way logic depends on lexical analysis or
the recognition of word boundaries.  "Lay out" is a verb while "layout" is
a noun.  The logic depends on the lexing.  Whitespace is not guaranteed to
be logically without effect.  Null is not whitespace, space is.  There are
enough situations where this introduces a semantic difference.

In the HTML specification it merely warns that some user agents may ignore
whitespace in certain circumstances.  I do not believe that you will find
this carried forward in either the work on XML normalisation nor in the
Internet-Draft from DRUMS updating RFC 822.  What I am saying is that the
best thinking on this issue is that a null string and linear whitespace are
logically different, a distinction that must be preserved.

Al

>
>My major reservation with this guideline is that there may be out there 
>many people who took the effort to write accessible pages with alt=""
>where appropriate, and now we tell them to revise their pages, without
>any reason whatsoever.
>
>Regards,
>Nir Dagan
>
>http://www.nirdagan.com
>mailto:nir@nirdagan.com
>tel:+972-2-588-3143
>
>"There is nothing quite so practical as a good theory."
>-- A. Einstein
>

Received on Thursday, 24 June 1999 08:57:44 UTC