- From: <Patrick.Stickler@nokia.com>
- Date: Wed, 14 Nov 2001 21:08:29 +0200
- To: Graham.Klyne@MIMEsweeper.com
- Cc: danbri@w3.org, phayes@ai.uwf.edu, w3c-rdfcore-wg@w3.org
Thanks. That does clarify things for me.
Patrick
> -----Original Message-----
> From: ext Graham Klyne [mailto:Graham.Klyne@MIMEsweeper.com]
> Sent: 14 November, 2001 19:34
> To: Stickler Patrick (NRC/Tampere)
> Cc: danbri@w3.org; phayes@ai.uwf.edu; w3c-rdfcore-wg@w3.org
> Subject: RE: ACTION 2001-11-02#02: Datatyping use-cases from CC/PP
>
>
> At 03:29 PM 11/14/01 +0200, Patrick.Stickler@nokia.com wrote:
> >No. But I'd hope that we *are* the right WG to define RDF Schema to
> >say things like 'an instance of the person class must have two
> >and only two values for the property x:parent and the values of
> >those properties may not be identitical (share the same URI).
>
> Not, as far as I am aware: the DAML+OIL and Web ontology groups are
> building those structures on top of RDF.
>
> >Right? Otherwise, we are left with *no* means whatsoever to
> >define constraints about manditory knowledge for specific
> >applications. XML Schema cannot define constraints for knowledge
> >bases build from the syndication of multiple instances, so
> >the constraint functionality offered by RDFS is critical.
>
> Yes: no such means within core RDF(S).
>
> >Am I really understanding you correctly as saying that RDFS
> >no longer defines any constraints whatsoever?
>
> That's my understanding.
>
> >Where then does the responsibility get shifted to? DAML+OIL?
> >The WebOnt WG deliverables?
>
> That's my expectation.
>
> ..
>
> You (and others) might argue that this means RDF(S) is only "half a
> solution". For some purposes, that may be true, but I
> strongly believe
> that for many other applications it is enough. The availability of a
> simple, consistent language for applications to express
> ground facts is a
> very powerful tool. Its's simplicity (from a developer
> perspective) will
> be, in my view, a key factor in getting lots of raw metadata
> out there on
> the web for more advanced reasoning engines to chew upon and
> generally work
> their magic. The logical consistency of this simple language
> is crucial to
> ensuring that more powerful generic layers (DAML_OIL, WebOnt
> and more) can
> be built on this foundation.
>
> Here are some notes I used to present RDF to our development team:
> http://public.research.mimesweeper.com/RDF/RDFMetadataForEndTo
EndContent.html
#g
------------------------------------------------------------
Graham Klyne MIMEsweeper Group
Strategic Research <http://www.mimesweeper.com>
<Graham.Klyne@MIMEsweeper.com>
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Received on Wednesday, 14 November 2001 14:08:25 UTC