FW: SKOS 'concept schemes' and DCMI 'vocabulary encoding schemes'

Hi all,

Sorry, should have cced this here when it was sent, comment on DCMI recommendations and aligning 'vocabulary encoding schemes' with 'concept schemes' ...

> -----Original Message-----
> From: Miles, AJ (Alistair) 
> Sent: 10 October 2005 16:07
> To: 'DC-RDF-TASKFORCE@JISCMAIL.AC.UK'
> Subject: SKOS 'concept schemes' and DCMI 'vocabulary encoding 
> schemes' 
> 
> 
> Hi all,
> 
> Just writing this up after thoughts at DC2005...
> 
> The problem:
> 
> Current qualified DC in RDF [1] recommends two patterns for 
> use of dc:subject ...
> 
> ---
> @prefix skos: <http://www.w3.org/2004/02/skos/core#> .
> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
> @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
> @prefix owl: <http://www.w3.org/2002/07/owl#> .
> @prefix dc: <http://purl.org/dc/elements/1.1/> .
> @prefix dcterms: <http://purl.org/dc/terms/> .
> 
> # DCMI Pattern 1:
> 
> <http://www.example.com/somedoc> dc:subject [
>   rdf:value '19D10';
>   rdfs:label 'Algebraic K-Theory of spaces';
>   rdfs:isDefinedBy <http://www.example.com/somedefiningresource>;
> ]. 
> 
> # DCMI Pattern 2:
> 
> <http://www.example.com/somedoc> dc:subject [
>   rdf:value 'D08.586.682.075.400';
>   rdfs:label 'Formate Dehydrogenase';
>   rdf:type dcterms:MESH;
> ].
> 
> # ... where ...
> 
> dcterms:MESH rdf:type rdfs:Class, dcterms:SubjectScheme;
>   rdfs:isDefinedBy <http://purl.org/dc/terms/>.
> ---
> 
> The usual pattern for declaring properties or classes in an 
> RDFS vocabulary is the following pattern:
> 
> ---
> @prefix eg: <http://www.example.com/eg#>
> 
> # RDFS pattern:
> 
> eg:aProperty rdf:type rdf:Property;
>   rdfs:label 'a property';
>   rdfs:isDefinedBy <http://www.example.com/eg>.
> 
> eg:aClass rdf:type rdfs:Class;
>   rdfs:label 'a class';
>   rdfs:isDefinedBy <http://www.example.com/eg>.
> ---
> 
> In OWL the pattern is the same, with a bit extra:
> 
> ---
> # OWL pattern:
> 
> eg:anObjectProperty rdf:type owl:ObjectProperty;
>   rdfs:label 'a property';
>   rdfs:isDefinedBy <http://www.example.com/eg>.
> 
> eg:aClass rdf:type owl:Class;
>   rdfs:label 'a class';
>   rdfs:isDefinedBy <http://www.example.com/eg>.
> 
> <http:www.example.com/eg> a owl:Ontology.
> ---
> 
> For declaring 'concepts' and 'concept schemes' using SKOS we 
> wanted to follow the same pattern as RDFS/OWL, i.e.:
> 
> ---
> # SKOS Pattern:
> 
> eg:aConcept rdf:type skos:Concept;
>   skos:prefLabel 'love';
>   skos:inScheme <http://www.example.com/conceptscheme>.
> 
> <http://www.example.com/conceptscheme> a skos:ConceptScheme.
> ---
> 
> The reason we added skos:inScheme (rather than just 
> recommending usage of rdfs:isDefinedBy) was to allow for the 
> possibility that a concept participates in more than one scheme.  
> 
> The DCMI pattern 1 fits with RDFS pattern, OWL pattern and 
> SKOS pattern.  However, DCMI pattern 2 doesn't.
> 
> I suggest that DCMI:
> 
>  - drops the notion of allowing a 'subject scheme' to also be 
> a 'class of values', 
> 
>  - drops the recommendation to use rdf:type to link a 
> 'subject' to a 'subject scheme', 
> 
>  - recommends only pattern 1, not pattern 2.
> 
> So then, the example expressed using DCMI pattern 2 above 
> would simply become:
> 
> ---
> <http://www.example.com/somedoc> dc:subject [
>   rdf:value 'D08.586.682.075.400';
>   rdfs:label 'Formate Dehydrogenase';
>   rdfs:isDefinedBy dcterms:MESH;
> ].
> 
> # ... where ...
> 
> dcterms:MESH rdf:type dcterms:SubjectScheme;
>   rdfs:isDefinedBy <http://purl.org/dc/terms/>.
> ---
> 
> That's my two cents.
> 
> Cheers,
> 
> Al.
> 
> 
> [1] http://dublincore.org/documents/2002/05/15/dcq-rdf-xml/
> 
> 
> 
> ---
> Alistair Miles
> Research Associate
> CCLRC - Rutherford Appleton Laboratory
> Building R1 Room 1.60
> Fermi Avenue
> Chilton
> Didcot
> Oxfordshire OX11 0QX
> United Kingdom
> Email:        a.j.miles@rl.ac.uk
> Tel: +44 (0)1235 445440
> 
>

Received on Monday, 10 October 2005 16:14:55 UTC