Re: practical question on naming graphs

Henry Story wrote:
> Has the W3c or anyone put together a practical guide on how to name graphs yet?

The RDF WG has a task force looking in to graph naming at the moment.

However..

> What should the graph names of some well known ontologies be?

Each well known ontology has it's "name" already defined within it, for 
example:

   <http://xmlns.com/foaf/0.1/> a owl:Ontology;
      dc:title "Friend of a Friend (FOAF) vocabulary" .

and

   <http://www.w3.org/2002/07/owl> a owl:Ontology;
     dc:title "The OWL 2 Schema vocabulary (OWL 2)" .

Further, you'll commonly find that each Class and Property defined 
within those ontologies has an rdfs:isDefinedBy statement.

Thus, you can avoid "named graphs" all together and simply search for 
all classes which are defined by the ontology in question, for example:

   SELECT DISTINCT ?class
   WHERE {
    ?class a rdfs:Class, owl:Class ; rdfs:isDefinedBy 
<http://xmlns.com/foaf/0.1/> .
   }

results for the above query on uri burner: http://bit.ly/lklavC

aside, you can of course use prefixes in the query to make it a bit 
easier to write off the cuff:

   SELECT DISTINCT ?class
   FROM foaf:
   WHERE {
    ?class a rdfs:Class, owl:Class ; rdfs:isDefinedBy foaf: .
   }

and just swap foaf: to owl: or whatever ontology you're looking for

Hope that helps a little,

Best,

Nathan

> Assuming to start off
> with that we don't want to explore issues of temporal graph names or names of graphs
> where the idenity of the requestor has been made available.
> 
> 
> For foaf should it be:
> 
>  +  http://xmlns.com/foaf/0.1/ 
>  +  http://xmlns.com/foaf/spec/ <- all foaf terms are redirected here with 303
>  +  http://xmlns.com/foaf/0.1/knows -> redirects with 303 to spec
> 
> Should owl be:
> 
>  + http://www.w3.org/2002/07/owl
>  + http://www.w3.org/2002/07/owl.rdf <- Content-Location but 200
> 
> Sould DC be:
>   
>   + http://purl.org/dc/elements/1.1/
>   + http://dublincore.org/2010/10/11/dcelements.rdf <- 302 Moved Temporarily
> 
> One answer may simply be both! That is in a SPARQL query
> 
> SELECT ?clazz
> FROM <http://xmlns.com/foaf/0.1/>
> WHERE { ?class a owl:Class }
> 
> SELECT ?clazz
> FROM <http://xmlns.com/foaf/spec/>
> WHERE { ?class a owl:Class }
> 
> should both return the same answers. The server serving the answers should do a GET or look up the information in a database that keeps track of redirects.
> 
> Note: for foaf type naming systems I suppose that means that it will take quite a few partial GETs one for each relation or class type, to GET all the initial 303 redirects before one really captures all the named graphs foaf can have.
> 
> Sorry to bring this up. I am sure it's been debated for ever already. If it has please just point me to the answer. :-)
> 
> Thanks, 
> 
> Henry
> 
> Social Web Architect
> http://bblfish.net/
> 
> 
> 
>

Received on Sunday, 15 May 2011 22:20:01 UTC