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Re: Meaning of Alt

From: Graham Klyne <GK@Dial.pipex.com>
Date: Thu, 07 Sep 2000 17:18:32 +0100
Message-Id: <4.3.2.7.2.20000907170929.00b405e0@pop.dial.pipex.com>
To: Ray Fergerson <fergerson@SMI.Stanford.EDU>
Cc: rdf interest <www-rdf-interest@w3.org>, Mor Peleg <peleg@SMI.Stanford.EDU>
I have two possible responses to this:

(a) "sameness", like so many other things in RDF, may be not defined at the 
level of the RDF model.  Different environments or applications may have 
different concepts of sameness.

(b) the lack of clarify about what rdf:Alt means, and the lack of a 
compelling prototypical application for it suggests to me that it might be 
struck from the core specification.  The applications you cite can both be 
handled without a special 'Alt' structure (same file, different URL:  just 
have two URL properties;  same word, different language:  use 
'interpretation properties' per 
http://www.w3.org/DesignIssues/InterpretationProperties.html.

#g
--

At 01:50 PM 9/6/00 -0700, Ray Fergerson wrote:
>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

------------
Graham Klyne
(GK@ACM.ORG)
Received on Thursday, 7 September 2000 12:38:08 GMT

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