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Re: Correct Usage of rdfs:idDefinedBy in Vocabulary Specifications with a Hash-based URI Pattern

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Thu, 30 Sep 2010 06:59:32 -0400
Message-ID: <4CA46D94.3030806@openlinksw.com>
To: Martin Hepp <martin.hepp@ebusiness-unibw.org>
CC: public-lod@w3.org, pedantic-web@googlegroups.com
  On 9/30/10 3:06 AM, Martin Hepp wrote:
> Dear all:
>
> We use rdfs:isDefinedBy in all of our vocabularies (*) for linking 
> between the conceptual elements and their specification.
>
> Now, there is a subtle question:
>
> Let's assume we have an ontology with the main URI
>
>     http://purl.org/vso/ns
>
> All conceptual elements are defined as hash fragment URIs (URI 
> references), e.g.
>
>     http://purl.org/vso/ns#Bike
>
> The ontology itself (the instance of owl:Ontology) has the URI
>
>     http://purl.org/vso/ns#
>
> <http://purl.org/vso/ns#>  a owl:Ontology ;
>     owl:imports <http://purl.org/goodrelations/v1> ;
>     dc:title "VSO: The Vehicle Sales Ontology for Semantic Web-based 
> E-Commerce"@en .
>
> So we have two URIs for the ontology:
>
> 1. http://purl.org/vso/ns# for the ontology as an abstract artefact
> 2. http://purl.org/vso/ns for the syntactical representation of the 
> ontology (its serialization)

Yes, you have two HTTP URIs associated with the Ontology. One is the 
"Name" of the Ontology Entity (Thing) and the other is the "Address" 
(URL) of the Ontology Descriptor Resource. Thus:

1. http://purl.org/vso/ns# -- Entity Name Reference
2. http://purl.org/vso/ns -- Descriptor Resource Address Reference .

>
> Shall the rdfs:isDefinedBy statements refer to #1 or #2 ?
>
> #1
> vso:Vehicle a owl:Class ;
>     rdfs:subClassOf gr:ProductOrService ;
>     rdfs:label "Vehicle (gr:ProductOrService)"@en ;
>     rdfs:isDefinedBy <http://purl.org/vso/ns#> . <===========
>
> #2
> vso:Vehicle a owl:Class ;
>     rdfs:subClassOf gr:ProductOrService ;
>     rdfs:label "Vehicle (gr:ProductOrService)"@en ;
>     rdfs:isDefinedBy <http://purl.org/vso/ns> . <===========
>
>
> I had assumed they shall refer to #1, but that caused some debate 
> within our group ;-)

You refer to Entities (Things) by Name Reference for Linked Data to work 
i.e. Names resolve to Descriptor Resources which may be serialized from 
Linked Data Server to User Agent using a variety of data formats such 
as: HTML+RDFa, RDF/XML, N3/Turtle, N-Triples, TriX etc..
>
> Opinions?

Also cc'd in the pedantic web folks for comments :-)

>
> Best
>
> Martin
>
>
>


-- 

Regards,

Kingsley Idehen	
President&  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen
Received on Thursday, 30 September 2010 11:00:10 UTC

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