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Re: Why contexts? (was: Klyne Contexts: 5.3-5.5 resources, languages and frames)

From: Graham Klyne <GK@Dial.pipex.com>
Date: Tue, 28 Nov 2000 20:02:58 +0000
Message-Id: <4.3.2.7.2.20001128195500.00e40620@pop.dial.pipex.com>
To: Pierre-Antoine CHAMPIN <champin@bat710.univ-lyon1.fr>
Cc: RDF interest group <www-rdf-interest@w3.org>
At 04:12 PM 11/24/00 +0100, Pierre-Antoine CHAMPIN wrote:
>Graham Klyne wrote:
> > One of my reasons for using contexts is that it gives me a framework for
> > making statements that do not depend on detailed ontological
> > structure.  Thus, in the 1st example you cite, I know that my car has an
> > engine and a body without necessarily knowing how they are ontologically
> > related to the car as a whole, and I can make meaningful statements 
> about them.
>
>Interesting point.
>Actually, I too had problems with the Car example, but that makes sense...
>
>I have another idea since a few days, which may be an alternate solution :
>the use of "anonymous" resources (which mean for me: I know there is a 
>resource here, but I don't know its URI).
>
>We can use anonymous resources as subject or object of a statement.
>Why not as the predicate ??
>
>   [my:Car] --[ ]--> [my:Engine]
>
>I have a car, I have an engine, I know there is a relation between them,
>but I have no word for that...
>
>  what do you RDFers think of that ?

An interesting approach.  A full answer to that goes far deeper than my 
small brain is capable of right now (currently about 40000 ft above the 
Atlantic Ocean).  But, in summary, I don't think that such an approach is 
in conflict with what I propose.

But, a question for you:  when you make your statement above, does it also 
allow a 'solution' of the form:

   [my:Car] --anonProperty--> [AnonResource] --anonProperty--> [my:Engine]

i.e. an *indirect* predicate relationship?

(I think either answer, yes or no, can be consistent with my approach, but 
may involve different additional machinery.  This touches on something I'm 
thinking about, and hopefully will get round to collecting my thoughts in 
some kind of discussion document.)

#g
--

> >
> > >One example says, in part:
> > >
> > >       [MyCar] --isa--> [FordEscort]
> > >       [     ] --rdfc:asserts-->
> > >         {
> > >         [TheBody] ----color-----> "red"
> > >         [TheEngine] --capacity--> "1600cc"
> > >         }
> > >
> > >
> > >The normal way to do this would be:
> > >
> > >  S1: [my:Car] --type--> [FordEscort]
> > >  S2: [my:Car] --body--> [my:Body]
> > >  S3: [my:Body] --color--> [red]
> > >  S4: [my:Car] --engine--> [my:Engine]
> > >  S5: [my:Engine] --capacity--> [my:Capacity]
> > >  S6: [my:Capacity] --unit--> [cc]
> > >  S7: [my:Capacity] --value--> "1600"
> >
> > By comparison, this form of description requires that the ontological
> > relationship between the components is known.

------------
Graham Klyne
(GK@ACM.ORG)
Received on Wednesday, 29 November 2000 16:07:35 GMT

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