W3C home > Mailing lists > Public > public-lod@w3.org > July 2008

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

From: Afraz Jaffri <afraz.jaffri@tiscali.co.uk>
Date: Thu, 10 Jul 2008 14:53:53 +0100 (GMT+01:00)
Message-ID: <20754013.1215698033939.JavaMail.root@ps34.mc.tiscali.sys>
To: semantic-web@w3.org, public-lod@w3.org

Apologies if this message gets duplicated...

We are pleased to announce a Linked Data site for the Ordnance Survey, 
available at:


with links from over 8000 URIs to Geonames URIs. Take 'Hampshire' as 
an example:


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.

Resolving this URI will give you a 'bundle' containing the duplicates:

    <coref:canon rdf:resource="http://os.rkbexplorer.
    <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>

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:

in particular http://dbpedia.org/resource/Welsh and http://dbpedia.


> -----Original Message-----
> From: public-lod-request@w3.org [mailto:public-lod-request@w3.org] 
> 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.
> 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 
> agree
> > with both of you.
> > Is that possible?
> >
> Bijan et. al. are right about the semantics of owl:sameAs, but as 
> said before, I think that something weaker needs to be coined
> ("lod:equivalentTo") that states that two URIs refer to the same 
> 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 
> Data community needs and what's happening organically in the wild 
> the (ab)use of owl:sameAs.
> > Hugh
> >
> >


Free games for a wet weekend - http://www.tiscali.co.uk/play
Received on Friday, 11 July 2008 22:21:08 UTC

This archive was generated by hypermail 2.4.0 : Thursday, 24 March 2022 20:29:40 UTC