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RE: DAML+OIL: Questions & Improvements.

From: Dan Brickley <danbri@w3.org>
Date: Sat, 27 Jan 2001 18:57:20 -0500 (EST)
To: "'www-rdf-logic@w3.org'" <www-rdf-logic@w3.org>
Message-ID: <Pine.LNX.4.30.0101271851550.23277-100000@tux.w3.org>
On Sat, 27 Jan 2001, Ian Horrocks wrote:

> Hi Dany,
> On January 26, King . Dany writes:
> > Hello Ian,
> >
> > Thanks for your comments...  I agree that RDF is a meta-language; however
> > it's purpose is to describe resources on the web.  DAML+OIL, on the other
> > hand, is meta-language for defining ontologies.  DAML+OIL could be
> > implemented in a number of ways.  At the moment, the DAML+OIL is being
> > implemented with RDF.  It is my understanding that the use of RDF is for
> > syntax only, because the semantics of DAML+OIL differs greatly from mere
> > resource description. Thus, the root DAML+OIL ontology should contain the
> > primitives of the meta-language used to define it (rdfs:Class, rdf:Property,
> > rdf:ID, etc.).  However, instances of DAML+OIL (ontologies built using the
> > DAML+OIL meta-language and their resulting instances) should only contain
> > DAML+OIL primitives (see question @@ in original email). Although there is a
> > 1 to 1 mapping on many  of the DAML+OIL primitives to the RDF primitives
> > (this is true only because RDF syntax is being used), there is at least one
> > case which has no mapping: the concept of a class.
> The thinking behind the use of RDFS is that it already has the basic
> elements of an ontology language - classes, properties, constraints,
> and subclass and subproperty relations - and that DAML+OIL should
> clarify (semantically) and extend (in some respects) what is there
> already.

...and the thinking behind RDFS was that it should only provide very
basic, skeletal machinery since the full picture is best be fleshed
out by richer modelling languages that layer on top of the RDF core.
DAML+OIL being an excellent example; one might also take Sergey Melnik's
UML-based approach as another case. How well this layering works is a
rather topic matter. My inclination would be to push a few concepts
(concrete datatypes, uniqueProperty...) down to the RDFS layer, then take
our time making sure DAML/OIL/etc provide a really expressive toolkit for
richer description of our RDF vocabularies.

Received on Saturday, 27 January 2001 18:57:21 UTC

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