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Re: Tidy/untidy: that's all about assumptions, folks

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Thu, 26 Sep 2002 12:09:36 +0300
Message-ID: <006001c2653c$6f923090$d74416ac@NOE.Nokia.com>
To: "ext Sergey Melnik" <melnik@db.stanford.edu>, "Jos De_Roo" <jos.deroo.jd@belgium.agfa.com>
Cc: "RDF Core" <w3c-rdfcore-wg@w3.org>



[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com]


----- Original Message ----- 
From: "ext Sergey Melnik" <melnik@db.stanford.edu>
To: "Jos De_Roo" <jos.deroo.jd@belgium.agfa.com>
Cc: "RDF Core" <w3c-rdfcore-wg@w3.org>
Sent: 26 September, 2002 11:34
Subject: Re: Tidy/untidy: that's all about assumptions, folks


> 
> Jos De_Roo wrote:
> 
> > Sergey, what are you saying?
> > I mean I already follow that you said like
> > 
> > :Maaike :age "45" .    #about my wife
> > :Jos :shoeSize "45" .
> > 
> > entails
> > 
> > _:x :age _:z .
> > _:y :shoeSize _:z .
> > 
> > which I wholeheartedly agree with
> > but what is that "critical assumption"
> > that you talk about?
> 
> 
> The assumption is that the values of age and shoeSize properties have to 
> denote "ages" and "shoe sizes", 

If the statements above do not in some way denote ages and
shoe sizes, in some fashion, at some level, then there is
no knowledge interchange.

And depending on the meta-properties of the property, one
might use a generic datatype, such as xsd:integer, along
with additional information about unit of measure and
other aspects. Or one might define a datatype, such as
foo:age, which actually has in its value space an enumeration
of complete years lived and some other datatype foo:shoesize,
which actually has in its value space an enumeration of 
shoe sizes.

In the case where both age and shoeSize properties would
use the generic datatype xsd:integer, then the above
entailment would hold. If more specific datatypes would
be used, the entailment would not hold, and any equality
suggested by the string-equal lexical representations
would be an illusion, an artifact of the form of 
expression.

But in either case, the interpretation of those lexical forms 
could be clearly expressed in the RDF rather than left implicit
and hidden in the extra-RDF application space, which
precludes effective interchange of knowledge.

Patrick
Received on Thursday, 26 September 2002 05:10:33 EDT

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