Re: [open-bibliography] MARC Codes for Forms of Musical Composition

I'm not sure where you get that it's appropriate (or preferred) to only have
one rdf:type per resource.

I am with you about foaf:Person and skos:Concept, only because I think
they're different things (that is, they are abstractly disjoint even if they
aren't ontologically).  Other people think differently.

However I don't think it's necessary to create a bunch of different URIs to
say that:

http://purl.org/NET/book/isbn/0192838024#book

is a:

http://purl.org/NET/book/vocab#Book
http://purl.org/ontology/bibo/Book
http://vocab.org/frbr/core#Manifestation
http://purl.org/goodrelations/v1#ProductOrServicesSomeInstancesPlaceholder
http://sites.wiwiss.fu-berlin.de/suhl/bizer/bookmashup/simpleCommerceVocab01.rdf#Book

etc.

-Ross.
On Wed, Jul 7, 2010 at 1:58 PM, Houghton,Andrew <houghtoa@oclc.org> wrote:
>
> > From: public-lld-request@w3.org [mailto:public-lld-request@w3.org] On
Behalf Of Ross Singer
> > Sent: Wednesday, July 07, 2010 11:29 AM
> > To: Young,Jeff (OR)
> > Cc: Erik Hetzner; public-lld
> > Subject: Re: [open-bibliography] MARC Codes for Forms of Musical
Composition
>
> > You can't have a foaf:Person that's also a foaf:Organization, anyway
(they are disjoint with each other).
>
> Kind of... in RDF you can say anything you like even if it is nonsensical
or completely wrong. An OWL validator on the other hand would surely
complain based on the disjointness constraint :)
>
> > We shouldn't need three URIs to define this person, but attributes of
all three classes are necessary (or useful) to accurately describe him/her.
>
> Well this probably gets into some sort of best practice where my personal
view is that it is better to keep individuals separate and have *only one*
rdf:type per individual, otherwise an individual's properties become one big
blob that you cannot pull apart using SPARQL. For example, while OWL DL
allows you to specify multiple rdf:type for an individual:
>
> <!--
>  Validate at:
>    <http://www.mygrid.org.uk/OWL/Validator>
>    Select OWL DL option
>  -->
> <rdf:RDF xml:base="http://example.org/ontology/"
>  xmlns:my="http://example.org/ontology/#"
>  xmlns:dct="http://purl.org/dc/terms/"
>  xmlns:foaf="http://xmlns.com/foaf/0.1/"
>  xmlns:owl="http://www.w3.org/2002/07/owl#"
>  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>  xmlns:skos="http://www.w3.org/2004/02/skos/core#"
>  xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
> >
>  <owl:Ontology rdf:about="" />
>  <owl:Class rdf:about="http://xmlns.com/foaf/0.1/Person" />
>  <owl:Class rdf:about="http://www.w3.org/2004/02/skos/core#Concept" />
>  <owl:DatatypeProperty rdf:about="http://purl.org/dc/terms/identifier" />
>  <foaf:Person rdf:about="#Person">
>    <dct:identifier>1</dct:identifier>
>  </foaf:Person>
>  <skos:Concept rdf:about="#Person">
>    <dct:identifier>5</dct:identifier>
>  </skos:Concept>
> </rdf:RDF>
>
> all properties specified in the foaf:Person description and skos:Concept
description will be merged in the RDF graph because they have the same
subject, e.g., #Person. This might be acceptable when you only use foaf:*
properties in the foaf:Person description and skos:* properties in the
skos:Concept description.  However, when using other generic properties such
as DC, UMBEL, etc. in either the foaf:Person description or the skos:Concept
description you cannot write a SPARQL query to tell which dct:* properties
were specified in the foaf:Person or skos:Concept descriptions.
>
> Maybe it doesn't matter in *your* application, but then maybe it *does
matter* in someone elses. From a best practice perspective, IMHO, it is
better to assign separate URIs to the foaf:Person and skos:Concept, then in
linked data fashion, use a linking property from an ontology to link the
foaf:Person and skos:Concept together. For example:
>
>  <owl:Thing rdf:about="#Person">
>    <rdfs:isDefinedBy rdf:resource="" />
>    <rdfs:seeAlso rdf:resource="#foaf:Person" />
>    <rdfs:seeAlso rdf:resource="#skos:Concept" />
>  </owl:Thing>
>
>  <foaf:Person rdf:about="#foaf:Person">
>    <dct:identifier>1</dct:identifier>
>    <rdfs:seeAlso rdf:resource="#Person" />
>  </foaf:Person>
>
>  <skos:Concept rdf:about="#skos:Concept">
>    <dct:identifier>5</dct:identifier>
>    <rdfs:seeAlso rdf:resource="#Person" />
>  </skos:Concept>
>
>
> Andy.
>
>
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