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Re: owl:sameAs [recipe]

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Tue, 28 Jul 2009 20:49:35 +0100
To: Kingsley Idehen <kidehen@openlinksw.com>
CC: Eric Lease Morgan <eric_morgan@infomotions.com>, "public-lod@w3.org" <public-lod@w3.org>
Message-ID: <EMEW3|1e8412d64e327d8fcc299bdc042907afl6RKnl02hg|ecs.soton.ac.uk|C836%hg@ecs.soton.ac.uk>
On 28/07/2009 14:46, "Kingsley Idehen" <kidehen@openlinksw.com> wrote:

> Hugh Glaser wrote:
>> Good stuff.
>> However, I don't think that Named Graphs are the answer.
>> I get my Linked Data by resolving URIs over http.
>> If I ask your Linked Data Space (I hope that is the right use of your
>> terminology) for something like
>> curl -H "Accept: application/rdf+xml" http://dbpedia.org/resource/London
>> and follow the redirect don't I still get the non-wikipedia data with the
>> wikipedia data?
>> Or am I not understanding something?
>>  
> The link chain shouldn't be broken. Named Graphs should have zero impact
> on HTTP URIs.
That is what I thought.
So how is the linkage data kept separate when I do URI resolution?
Cheers
> 
> I think Alan is saying: put what is best described as a linkbase dump in
> a separate Named Graph. Doing this shouldn't break the tapestry inherent
> in the HTTP URIs (the data  conductors). We have tons of data in
> <http://lod.openlinksw.com> partitioned across named graphs, and none of
> that breaks the "follow-your-nose" pattern. Remember, I am a stickler
> for keeping the HTTP URIs of entities in full scope of user agents :-)
> 
> The only time you might have an issue is when performing SPARQL, where
> explicitly identifying the Named Graph in the FROM Clause may aid
> performance (and even here this depends on the indexing in placece re,
> the RDF DBMS insta, these days re. Virtuoso that doesn't even matter
> since the default indexing scheme has been changed).
> 
> Kingsley
>> Best
>> Hugh
>> 
>> 
>> On 28/07/2009 11:17, "Kingsley Idehen" <kidehen@openlinksw.com> wrote:
>> 
>> Hugh Glaser wrote:
>>  
>>> For the record (  Alan!).
>>> I consider it bad practice to keep the knowledge about linking in the same
>>> KB as the substantive knowledge you are representing.
>>> You need two KBs: one for the knowledge you are publishing, and one for the
>>> linkage you are working on.
>>> These have very different provenance, maintenance patterns, etc..
>>> And you can include a link from URIs that you generate to the linkage KB.
>>> 
>>>    
>> For terminology consolidation purposes, what you call a  KB is  a
>> "Linked Data Space" in my parlance :-)
>> 
>> Yes, the partitioning suggested above is very important. Thus, you need
>> purpose specific Linked Data Spaces  (hosing many Named Graphs) if you
>> seek to make things a little clearer to data consumers and their agents.
>>  
>>> In fact, this would then help Alan's problem about sameAs:- he could simply
>>> decide not to get your view of the linkage, whereas with sameAs in the
>>> resources he has no choice but to accept your view, and even your predicate
>>> when he resolves a URI or queries the SPARQL.
>>> 
>>> And I do agree with you about minting URIs to your local stuff, including
>>> authors; it is error-prone to try to re-use things like dbpedia for this, on
>>> any scale. And this is why you need to tackle the linkage problem as a
>>> separate engineering activity.
>>> 
>>> Best
>>> Hugh
>>> 
>>> (Of course I do have some software and architecture that supports separate
>>> linkage KBs (our CRS) so I would say this, but nevertheless I think it is
>>> the correct engineering approach, however it is done. Separation of
>>> Concerns.)
>>> 
>>>    
>> 
>> Note, we've partitioned DBpedia in such a way that you now have a Graph
>> IRI for each data set within this particular Linked Data Space.
>> 
>> Kingsley
>>  
>>> On 28/07/2009 02:23, "Eric Lease Morgan" <eric_morgan@infomotions.com>
>>> wrote:
>>> 
>>> 
>>> 
>>> On Jul 25, 2009, at 5:09 AM, Bill Roberts wrote:
>>> 
>>> 
>>>    
>>>> 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...
>>>> 
>>>>      
>>> Okay, then how's this for a recipe to create rich linked data of
>>> electronic books and authors within my own site as well as to the
>>> outside world:
>>> 
>>>    1. Mint URIs pointing to representations of local etexts
>>>    2. Mint URIs pointing to representations of authors of local etexts
>>> 
>>>    3. In resources of etexts, include owl:sameAs links to DBpedia
>>> resources
>>>    4. In resources of etexts, point to local URIs of authors
>>> 
>>>    5. In resources of authors, include owl:sameAs links to DBpedia
>>> resources
>>>    6. In resources of authors, include owl:creatorOf links to local
>>> etexts
>>> 
>>>    7. For extra credit, do the same thing for subjects/keywords
>>> 
>>> For example, the following resource descriptions:
>>> 
>>> <!-- etext #1; points to local author and remote title -->
>>> <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="http://dbpedia.org/resource/Utopia_(book)">
>>>      <dcterms:title>Utopia</dcterms:title>
>>>      <dcterms:creator
>>> rdf:resource="http://infomotions.com/etexts/authors/resource/thomas-more
>>> " />
>>>    </rdf:Description>
>>> </rdf:RDF>
>>> 
>>> 
>>> <!-- etext #2; points to local author and remote title -->
>>> <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-reality-404"
>>>      owl:sameAs="http://dbpedia.org/resource/Reality_(book)">
>>>      <dcterms:title>Reality</dcterms:title>
>>>      <dcterms:creator
>>> rdf:resource="http://infomotions.com/etexts/authors/resource/thomas-more
>>> " />
>>>    </rdf:Description>
>>> </rdf:RDF>
>>> 
>>> 
>>> <!-- author; points to local etexts and remote author -->
>>> <rdf:RDF
>>>    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>>>    xmlns:owl="http://www.w3.org/2002/07/owl#">
>>>    <rdf:Description
>>>      rdf:about="http://infomotions.com/etexts/authors/resource/thomas-more
>>> "
>>>      owl:sameAs="http://dbpedia.org/resource/Thomas_More">
>>>      <owl:creatorOf
>>> rdf:resource="http://infomotions.com/etexts/id/more-utopia-221
>>> "/>
>>>      <owl:creatorOf
>>> rdf:resource="http://infomotions.com/etexts/id/more-reality-404
>>> " />
>>>    </rdf:Description>
>>> </rdf:RDF>
>>> 
>>> --
>>> Eric Lease Morgan
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>    
>> 
>> 
>> --
>> 
>> 
>> Regards,
>> 
>> Kingsley Idehen       Weblog: http://www.openlinksw.com/blog/~kidehen
>> President & CEO
>> OpenLink Software     Web: http://www.openlinksw.com
>> 
>> 
>> 
>> 
>> 
>> 
>>  
> 
> 
> --
> 
> 
> Regards,
> 
> Kingsley Idehen       Weblog: http://www.openlinksw.com/blog/~kidehen
> President & CEO
> OpenLink Software     Web: http://www.openlinksw.com
> 
> 
> 
> 
> 
Received on Tuesday, 28 July 2009 19:50:30 UTC

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