W3C home > Mailing lists > Public > public-lld@w3.org > March 2011

RE: Ontological constraints

From: Young,Jeff (OR) <jyoung@oclc.org>
Date: Wed, 16 Mar 2011 12:54:08 -0400
Message-ID: <52E301F960B30049ADEFBCCF1CCAEF590BD0C5EA@OAEXCH4SERVER.oa.oclc.org>
To: "Svensson, Lars" <L.Svensson@dnb.de>, "Karen Coyle" <kcoyle@kcoyle.net>, "public-lld" <public-lld@w3.org>
Lars,

Here's a section in the OWL Guide that probably explains it better than I can.

http://www.w3.org/TR/owl-guide/

Basically, owl:ObjectProperty and owl:DatatypeProperty can (and generally should) be used in place of rdfs:Property to avoid the label/thing confusion we saw in older RDF vocabularies. An example is dc:creator <http://dublincore.org/documents/dcmi-terms/#elements-creator>:

<uri-1>
	dc:creator "John Doe" ;
	dc:creator <uri-2> .

In principle, the newer dcterms:creator element could be upgraded to owl:ObjectProperty because its rdfs:range setting doesn't allow literals <http://dublincore.org/documents/dcmi-terms/#terms-creator>.

I can try to give more examples and context if necessary.

Jeff


> -----Original Message-----
> From: Svensson, Lars [mailto:L.Svensson@dnb.de]
> Sent: Wednesday, March 16, 2011 11:15 AM
> To: Young,Jeff (OR); Karen Coyle; public-lld
> Subject: AW: Ontological constraints
> 
> Jeff,
> 
> for those of us (i. e. me) who are not so deep into OWL: What's the
> difference between owl:ObjectProperty and
> owl:DatatypeProperty? I guess it's got something to do with is-a vs.
> has-a.
> 
> Thanks,
> 
> Lars
> 
>   **** Bitte beachten Sie die neue Internet- und E-Mail-Adresse. ****
>   **** Please note my new internet- and email-address. ****
> 
> --
> Dr. Lars G. Svensson
> Deutsche Nationalbibliothek / Informationstechnik
> http://www.dnb.de/
> l.svensson@dnb.de
> 
> 
> > -----Ursprüngliche Nachricht-----
> > Von: Young,Jeff (OR) [mailto:jyoung@oclc.org]
> > Gesendet: Mittwoch, 16. März 2011 15:35
> > An: Svensson, Lars; Karen Coyle; public-lld
> > Betreff: RE: Ontological constraints
> >
> > One aspect of this is that it isn't necessarily essential to include
> > rdf:type properties when we name individuals using a URI. Many of
> them
> > can be inferred on-demand from the domain/range of its properties. In
> > those cases, including them in an RDF document representation is just
> > another form of caching.
> >
> > I think it makes sense to emphasize properties over classes,
> especially
> > if those properties are defined as owl:ObjectProperty vs.
> > owl:DatatypeProprety. "is-a" is nice to know and handy for dealing
> with
> > sets of individuals, but "has-a" says how and why somebody believes A
> > and B are two different things. If the property relationship
> connecting
> > the two individuals is believable, then it helps inform our
> > understanding of the "is-a" relationships assigned to the
> individuals.
> >
> > I think it's interesting to look at the DBpedia entry for "Pride and
> > Prejudice" and ask which properties are problematic and why. How we
> > could tweak them to make more sense without starting from scratch?
> >
> > http://dbpedia.org/page/Pride_and_Prejudice
> >
> > Jeff
> >
> > > -----Original Message-----
> > > From: Svensson, Lars [mailto:L.Svensson@dnb.de]
> > > Sent: Wednesday, March 16, 2011 4:15 AM
> > > To: Young,Jeff (OR); Karen Coyle; public-lld
> > > Subject: AW: Ontological constraints
> > >
> > > Karen, Jeff,
> > >
> > > A late note on this:
> > >
> > > > I think the key phrase is "sufficient to support the intended
> > > knowledge
> > > > sharing activities".
> > > >
> > > > One area of disagreement seems to be on the need to proliferate
> > > > properties to encode the domain and/or range in the property name
> > > > itself.
> > >
> > > Tom quoted Karen in saying
> > >
> > > [[
> > > On Sun, Mar 06, 2011 at 09:35:22AM -0800, Karen Coyle wrote:
> > > > I actually think that we should emphasize the "has a" rather than
> > "is
> > > > a" aspects of the resources we describe, and let the "has a"
> allow
> > us
> > > > to infer any number of "is a" qualities. This is the message that
> > Jon
> > > > Phipps gave at the tutorial day at DC in Pittsburgh -- that we
> > > > describe things by their characteristics, and those
> characteristics
> > > > tell us what the thing *is*.
> > >
> > > Yes, that sounds right to me.  Emphasize Properties
> > > (relationships) over Classes. Verbs over nouns.  Describe
> > > things less through giving them a name -- i.e., writing a
> > > definition for a class of things to which they belong --
> > > and more through enumerating their characteristics.
> > > ]] [1]
> > >
> > > If this is so, then I'd say that we _definitely_ need to state
> > > domain/range for the properties, otherwise The System (TM) will not
> > be
> > > able to find out what the thing is, even if it knows the
> > > characteristics. Does that make sense?
> > >
> > > [1] http://lists.w3.org/Archives/Public/public-
> lld/2011Mar/0025.html
> > >
> > > All the best,
> > >
> > > Lars
> > >
> > >
> > >   **** Bitte beachten Sie die neue Internet- und E-Mail-Adresse.
> ****
> > >   **** Please note my new internet- and email-address. ****
> > >
> > > --
> > > Dr. Lars G. Svensson
> > > Deutsche Nationalbibliothek / Informationstechnik
> > > http://www.dnb.de/
> > > l.svensson@dnb.de
> > >
> > >
> > > > -----Ursprüngliche Nachricht-----
> > > > Von: public-lld-request@w3.org [mailto:public-lld-request@w3.org]
> > Im
> > > > Auftrag von Young,Jeff (OR)
> > > > Gesendet: Donnerstag, 10. März 2011 20:11
> > > > An: Karen Coyle; public-lld
> > > > Betreff: RE: Ontological constraints
> > > >
> > > > I think the key phrase is "sufficient to support the intended
> > > knowledge
> > > > sharing activities".
> > > >
> > > > One area of disagreement seems to be on the need to proliferate
> > > > properties to encode the domain and/or range in the property name
> > > > itself.
> > > >
> > > > Jeff
> > > >
> > > > > -----Original Message-----
> > > > > From: public-lld-request@w3.org [mailto:public-lld-
> > request@w3.org]
> > > On
> > > > > Behalf Of Karen Coyle
> > > > > Sent: Thursday, March 10, 2011 2:03 PM
> > > > > To: public-lld
> > > > > Subject: Ontological constraints
> > > > >
> > > > > Pursuant to our discussion today on the WG conference call
> about
> > > FR's
> > > > > and ontological constraints, this quote I first saw when Tom
> > Baker
> > > > > posted it, and later I discovered the actual article it was
> from:
> > > > >
> > > > > 5. Minimal ontological commitment: An ontology should require
> the
> > > > > minimal ontological commitment sufficient to support the
> intended
> > > > > knowledge sharing activities. An ontology should make as few
> > claims
> > > > as
> > > > > possible about the world being modeled, allowing the parties
> > > > committed
> > > > > to the ontology freedom to specialize and instantiate the
> > ontology
> > > as
> > > > > needed. Since ontological commitment is based on consistent use
> > of
> > > > > vocabulary, ontological commitment can be minimized by
> specifying
> > > the
> > > > > weakest theory (allowing the most models) and defining only
> those
> > > > > terms that are essential to the communication of knowledge
> > > consistent
> > > > > with that theory.
> > > > >
> > > > > Gruber, Thomas R. ?Toward principles for the design of
> ontologies
> > > > used
> > > > > for knowledge sharing.? International Journal Human-Computer
> > > Studies
> > > > > 43 (1993): 907-928.
> > > > > (p.3)
> > > > >
> > > > > I think what our discussion was dancing around was whether we
> > think
> > > > > that the FRBR entity constraints constitute the appropriate
> level
> > > of
> > > > > commitment. Some think that it is, others feel that it
> > > > > over-constrains. Perhaps the message from the group (for the
> > > report)
> > > > > is that the level of constraint needs to be investigated in
> > > relation
> > > > > to the "knowledge sharing activities".
> > > > >
> > > > > kc
> > > > >
> > > > > --
> > > > > Karen Coyle
> > > > > kcoyle@kcoyle.net http://kcoyle.net
> > > > > ph: 1-510-540-7596
> > > > > m: 1-510-435-8234
> > > > > skype: kcoylenet
> > > > >
> > > > >
> > > >
> > > >
> > >
> >
> 
Received on Wednesday, 16 March 2011 16:55:32 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 16 March 2011 16:55:34 GMT