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Re: Meaning of Alt

From: Ray Fergerson <fergerson@SMI.Stanford.EDU>
Date: Wed, 06 Sep 2000 13:50:34 -0700
Message-ID: <39B6AE1A.E5F9DBDE@smi.stanford.edu>
To: rdf interest <www-rdf-interest@w3.org>
CC: Graham Klyne <GK@dial.pipex.com>, Mor Peleg <peleg@SMI.Stanford.EDU>
Graham Klyne wrote:
> I think that describing a union data type and listing several alternative
> representations of what is essentially the same value are two very
> different functions that have somehow been conflated with the idea of
> 'alternative'.

This is really the question.  Was it the intention of the authors of
the spec that Alt should have semantics in addition to "these are the
possible values of a property"?  It appears that the answer is yes and
that the semantics are related to "sameness" and "differentness" but
this is not clearly spelled out.  There also appears to be no
mechanism for encoding the axes of "sameness" and "differentness".  

The examples from the spec are: (1) same word, different language and
(2) same file, different urls.  When I consider the following things:

(1) URLs for downloading Netscape 4.72
(2) URLs for downloading Netscape 4.7
(3) URLs for downloading Netscape 4
(4) URLs for downloading Netscape
(5) URLs for downloading Browsers
(6) URLs for downloading Software
(7) URLs
(9) strings

I can't really decide if any of these is a candidate for the items of
an Alt collection.

I think that the implication in the spec that there are additional
semantics associated with Alt should just be removed.  It would be
useful to have a collection type whose semantics are roughly limited
to "these are the choices for a property value" with no implication of
"sameness" for those values. 

Ray
Received on Wednesday, 6 September 2000 16:48:39 GMT

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