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Re: Ordnance Survey data as Linked Data (RE: How do you deprecate URIs? Re: OWL-DL and linked data)

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Sun, 13 Jul 2008 10:56:38 -0700
Message-ID: <487A41D6.5090008@openlinksw.com>
To: afraz.jaffri@tiscali.co.uk
CC: public-lod@w3.org, semantic-web@w3.org

Afraz Jaffri wrote:
> Sorry, the link i gave was to the HTML description,the URI of the 
> resource is
>
> http://os.rkbexplorer.com/id/osr7000000000017765
> then:
> [aoj04r@cohen ~]$ curl -I -H "Accept: application/rdf+xml" http://os.
> rkbexplorer.com/id/osr7000000000017765
> HTTP/1.1 303 See Other
> Date: Sun, 13 Jul 2008 10:44:10 GMT
> Server: Apache/2.0.52 (Red Hat)
> X-Powered-By: PHP/4.3.9
> Location: /data/osr7000000000017765
> Connection: close
> Content-Type: text/html; charset=UTF-8
>
> Afraz.
>   
Afraz,

Yes, but it is also good practice to link the HTML description with the 
RDF representation of the description. This enables the RDF discovery to 
start from the HTML description.

This is all that is required:
 <link rel="alternate"  type="application/rdf+xml" 
href="http://os.rkbexplorer.com/data/osr7000000000017765" /> 

Of course you can also use RDFa to similar effect by making a seeAlso claim.

Kingsley
> Afraz Jaffri wrote:
>   
>> We are pleased to announce a Linked Data site for the Ordnance 
>>     
> Survey, 
>   
>> available at:
>>
>> http://os.rkbexplorer.com
>>
>> with links from over 8000 URIs to Geonames URIs. Take 'Hampshire' 
>>     
> as 
>   
>> an example:
>>   
>>     
> Afraz,
>   
>> http://os.rkbexplorer.com/description/osr7000000000017765
>>
>>   
>>     
> kidehen$ curl -I -H "Accept: application/rdf+xml" 
> http://os.rkbexplorer.com/description/osr7000000000017765
> HTTP/1.1 406 Not Acceptable
> Date: Sat, 12 Jul 2008 20:31:35 GMT
> Server: Apache/2.0.52 (Red Hat)
> X-Powered-By: PHP/4.3.9
> Content-Type: text/html; charset=UTF-8
> Connection: close
>
> Why no 303 or use of <link rel="[relavant-predicate]" .../>  so that 
> User Agents can locate <http://os.rkbexplorer.
> com/data/osr7000000000017765> .
>
> My issues are summarized here:
>
> http://demo.openlinksw.com/rdfbrowser2/?uri%5B%5D=http%3A%2F%2Fos.
> rkbexplorer.com%2Fdescription%2Fosr7000000000017765&uri%5B%5D=http%3A%
> 2F%2Fos.rkbexplorer.com%2Fdata%2Fosr7000000000017765&
>
> Kingsley
>   
>> It might also be the right time, with all the owl:sameAs 
>>     
> discussion, 
>   
>> to practically demonstrate how our coreference system works. In the 
>> above example the link created is between 'Hampshire the county' 
>>     
> from 
>   
>> the OS and 'Hampshire the second order administrative division' 
>>     
> from 
>   
>> Geonames. We do not know if these two entities are exactly the 
>>     
> same, 
>   
>> so instead of using owl:sameAs we use our own coref:duplicate 
>> predicate.
>>
>> One of the features of our system is that knowledge about 
>>     
> coreference 
>   
>> is separated from the knowledge of the actual entity. In the RDF 
>>     
> for 
>   
>> the above URI at http://os.rkbexplorer.com/data/osr7000000000017765
>> you
>> will find:
>>
>> <coref:coreferenceData rdf:resource="http://os.rkbexplorer.
>> com/crs/osr7000000000017765"/>
>>
>> Resolving this URI will give you a 'bundle' containing the 
>>     
> duplicates:
>   
>> <coref:Bundle>
>>     <coref:canon rdf:resource="http://os.rkbexplorer.
>> com/id/osr7000000000017765"/>
>>     <coref:duplicate rdf:resource="http://os.rkbexplorer.
>> com/id/osr7000000000017765" />
>>     <coref:duplicate rdf:resource="http://sws.geonames.org/2647554/"
>>     
> />
>   
>>     <coref:lastUpdated>2008-07-10 11:39:44</coref:lastUpdated>
>>   </coref:Bundle>
>>
>> As you can see one URI is chosen as the canonical URI to use. The 
>> separation of coreference means, to a limited extent, that the 
>>     
> context 
>   
>> of duplication can be preserved. If I wanted to say that under some 
>> other context there were other URIs that were deemed to be the same 
>> then I can simply create another bundle with another <coref:
>> coreferenceData> predicate in the RDF for the entity. Of course, the
>> question of how to show the context is yet to be solved...
>>
>> There may be some errors in the equivalences. All feedback is 
>> greatfully received :)
>>
>> In relation to another question about how owl:sameAs is currently 
>> being used, there are some examples in our LDOW paper:
>> http://eprints.ecs.soton.ac.uk/15181/
>>
>> in particular http://dbpedia.org/resource/Welsh and http://dbpedia.
>> org/resource/Lilac
>>
>> Regards,
>> Afraz
>>
>>
>>   
>>     
>>> -----Original Message-----
>>> From: public-lod-request@w3.org [mailto:public-lod-request@w3.org]
>>>     
>>>       
>> On
>>   
>>     
>>> Behalf Of Harry Halpin
>>> Sent: 09 July 2008 10:55
>>> To: Hugh Glaser
>>> Cc: Bijan Parsia; Peter Ansell; semantic-web at W3C; public-lod@w3.
>>>     
>>>       
>> org
>>   
>>     
>>> Subject: Re: How do you deprecate URIs? Re: OWL-DL and linked data
>>>
>>>
>>> Hugh Glaser wrote:
>>>     
>>>       
>>>> Thanks guys, a really interesting and important discussion.
>>>> However, after the last couple of postings I have the feeling I
>>>>       
>>>>         
>> may
>>   
>>     
>>> agree
>>>     
>>>       
>>>> with both of you.
>>>> Is that possible?
>>>>
>>>>       
>>>>         
>>> Bijan et. al. are right about the semantics of owl:sameAs, but as
>>>     
>>>       
>> I've
>>   
>>     
>>> said before, I think that something weaker needs to be coined
>>> ("lod:equivalentTo") that states that two URIs refer to the same
>>>     
>>>       
>> thing
>>   
>>     
>>> but that any semantic entailments *may* not hold (i.e. user 
>>>       
> beware).
>   
>>> That's a dangerous thing, I agree, but it seems to be what the
>>>     
>>>       
>> Linked
>>   
>>     
>>> Data community needs and what's happening organically in the wild
>>>     
>>>       
>> with
>>   
>>     
>>> the (ab)use of owl:sameAs.
>>>
>>>     
>>>       
>>>> Hugh
>>>>
>>>>
>>>>       
>>>>         
>>
>> __________________________________________________________
>>
>> Free games for a wet weekend - http://www.tiscali.co.uk/play 
>> __________________________________________________________
>>
>>
>>
>>
>>
>> __________________________________________________________
>>
>> Free games for a wet weekend - http://www.tiscali.co.uk/play 
>> __________________________________________________________
>>
>>
>>
>>
>>   
>>     
>
>
>   


-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Sunday, 13 July 2008 17:57:27 UTC

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