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RE: owl:sameAs

From: <bill.roberts@planet.nl>
Date: Mon, 27 Jul 2009 16:55:21 +0200
Message-ID: <09584178D434304885A073316C800D0C15113F2F@CPEXBE-EML13.kpnsp.local>
To: "Eric Lease Morgan" <eric_morgan@infomotions.com>, <public-lod@w3.org>
Hi Eric
 
Regarding your first point - yes, your two options are equivalent and the second one is neater, so go for that.
 
Regarding linking to external resources, what it seems you want to do is to identify the dc:creator of the book, hence say that the creator is the person whose name was Thomas More.  You could create your own URI and if you are managing a whole bunch of data about books and authors, then there could be reasons to do that, but in general if there is a satisfactory existing URI, it is preferable to use it.  Dbpedia seems to have become the de facto standard so you could simply say:
 
<rdf:RDF
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns <https://webmail.planet.nl/exchweb/bin/redir.asp?URL=http://www.w3.org/1999/02/22-rdf-syntax-ns> #"
   xmlns:dcterms="http://purl.org/dc/terms/ <https://webmail.planet.nl/exchweb/bin/redir.asp?URL=http://purl.org/dc/terms/> "
   xmlns:owl="http://www.w3.org/2002/07/owl <https://webmail.planet.nl/exchweb/bin/redir.asp?URL=http://www.w3.org/2002/07/owl> #">
   <rdf:Description rdf:about="http://infomotions.com/etexts/id/more-utopia-221 <https://webmail.planet.nl/exchweb/bin/redir.asp?URL=http://infomotions.com/etexts/id/more-utopia-221> 
">
     <owl:sameAs rdf:resource="http://dbpedia.org/resource/ <https://webmail.planet.nl/exchweb/bin/redir.asp?URL=http://dbpedia.org/resource/> 
Utopia_(book)" />
     <dcterms:creator rdf:resource="http://dbpedia.org/resource/Thomas_More" />
     <dcterms:subject>people</dcterms:subject>
     <dcterms:subject>pleasure</dcterms:subject>
   </rdf:Description>
</rdf:RDF>

If you want to go further and say that the person with that URI has name "More, Thomas" then you can add that as an additional triple with http://dbpedia.org/resource/Thomas_More as the subject, perhaps using the FOAF vocabulary.
 
Because owl:sameAs is used for saying that two URIs label the same thing, then you can't use it with literals. 
 
When it comes to the subjects, I expect that finding good, unambiguous URIs for concepts like 'people' or 'pleasure' is a bit more difficult. Perhaps other readers of the list might know about useful existing tagging/classification schemes you could use.  
 
I hope I'm understanding your problem correctly and hope these suggestions are helpful.
 
Regards
 
Bill Roberts

________________________________

Van: public-lod-request@w3.org namens Eric Lease Morgan
Verzonden: ma 27-7-2009 15:54
Aan: public-lod@w3.org
Onderwerp: Re: owl:sameAs




On Jul 25, 2009, at 5:09 AM, Bill Roberts wrote:

>> I would like to make my Alex Catalogue more accessible as linked 
>> data, but I need some help in regards to the syntactical use of 
>> owl:sameAs.
>
> Simply use owl:sameAs like you would any other property.  The object 
> of the triple is the URI you want to say refers to the same thing.  So
>
>  <rdf:Description rdf:about="http://infomotions.com/etexts/id/more-utopia-221
> >
>     <owl:sameAs resource="http://dbpedia.org/resource/Utopia_(book)">
>  </rdf:Description>


Thank you for the prompt reply, but I still need some additional help 
regarding syntax.

My goal is to link my resources as well as literals to outside 
resources. To link my books to additional versions of the books seems 
easy. Either of the following two example validate, but the later -- 
with an attribute -- seems simpler:

<rdf:RDF
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:dcterms="http://purl.org/dc/terms/"
   xmlns:owl="http://www.w3.org/2002/07/owl#">

   <rdf:Description rdf:about="http://infomotions.com/etexts/resource/more-utopia-221
">
     <dcterms:creator>More, Thomas</dcterms:creator>
     <dcterms:subject>people</dcterms:subject>
     <dcterms:subject>pleasure</dcterms:subject>
   </rdf:Description>

   <rdf:Description rdf:about="http://infomotions.com/etexts/resource/more-utopia-221
">
     <owl:sameAs rdf:resource="http://dbpedia.org/resource/
Utopia_(book)" />
   </rdf:Description>

</rdf:RDF>


<rdf:RDF
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:dcterms="http://purl.org/dc/terms/"
   xmlns:owl="http://www.w3.org/2002/07/owl#">
   <rdf:Description rdf:about="http://infomotions.com/etexts/id/more-utopia-221
">
     <owl:sameAs rdf:resource="http://dbpedia.org/resource/
Utopia_(book)" />
     <dcterms:creator>More, Thomas</dcterms:creator>
     <dcterms:subject>people</dcterms:subject>
     <dcterms:subject>pleasure</dcterms:subject>
   </rdf:Description>
</rdf:RDF>


I suppose it is six of one and half a dozen of the other.

More importantly, how do link the creator and subject literals to 
outside resources? Adding owl:sameAs proves to invalidate the dcterms 
schema. Maybe I need to create local resources for each of my creators 
and subjects, and then link those to outside resources?

--
Eric Morgan
Received on Monday, 27 July 2009 14:56:13 UTC

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