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Re: How to state simple facts in RDF

From: Dan Brickley <danbri@w3.org>
Date: Wed, 29 Jun 2005 14:15:45 +0100
Message-ID: <42C29F01.4070205@w3.org>
To: Lars Marius Garshol <larsga@ontopia.net>
Cc: public-swbp-wg@w3.org

Lars Marius Garshol wrote:

>* Michael F. Uschold
>|
>| Rdf:type is fine for many such examples.
>
>It does seem to work, and work well, in some of the cases, I agree.
> 
>| However, it is not always such a good idea to create special
>| classes/types for every such fact.
>| For example: 
>| 	My car is red.
>| 	This food tastes good.
>| 
>| To use rdf:type food these statements requires one to create
>| artificial classes/types for such notions as RedThings, or
>| GoodTastingThings.
>| 
>| One can do it, but it is not always what you want.
>
>I agree, and the RDFTM work is one case where this isn't really what
>we want, since although it works to turn
>
>  is-bankrupt(barings-bank : company) /* LTM syntax */
>
>into
>
>  (barings-bank, rdf:type, BankruptCompany)
>
>this causes difficulties with roundtripping back to topic maps, since
>we can't then easily distinguish between types that are "real types"
>and types that really represent "unary associations".
>
>Does anyone know of other good modelling patterns for this in RDF? Or
>do we need to create a special
>rdftm:ArtificialClassThatIsReallyAUnaryAssociationType class?
>
>  
>
Not such a bad idea. Except I'm not sure "really being
a unary association" is easy to define. In prolog, one
might write "person(dan)" while in RDF I'd use the
class foaf:Person. How can we judge whether the class
is an artificial one or not? One answer might be with
appeal to the body of tools, practice, super/sub classes
around it, etc. However those are things that evolve over time.

Dan
Received on Wednesday, 29 June 2005 13:15:47 UTC

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