Re: Linked Data Aspects of R2RML

This is the owl:sameAs problem, which I think we should not spend time
discussing at the moment.

As Michael said, let's pin down what the charter really means. I did get a
head of myself thinking more of the application side. However, I think that
we should offer a mechanism of reusing existing identifiers.


Juan Sequeda, Ph.D Student
Dept. of Computer Sciences
The University of Texas at Austin
www.juansequeda.com
www.semanticwebaustin.org


On Fri, Jan 15, 2010 at 10:17 AM, Fogarolli Angela
<afogarol@disi.unitn.it>wrote:

> Good point Eric!
> I did not want to bother you and we can discuss this kind of issue in the
> call, but i want to make a point...
> it's not semantically correct (or not always) to say that:
>
> http://myrentalstore.com/resource/film/123 owl:samesAs
>  http://dbpedia.org/resource/Breakfast_at_Tiffany%27s_%28film%29
> because the "owl:sameAs" means that we accept the union between the two
> description which is not always the case...
> We faced this issue in OKKAM and using the OKKAM system we don't make the
> union between different descriptions (provided by the alternative ID uri)
> but you simply refer to different descriptions in different data sources.
> And OKKAM says that all the descriptions refers to the same thing but NOT
> THAT the thing is described by the union of those different descriptions...
>
> Bye
> Angela.
>
> <http://dbpedia.org/resource/Breakfast_at_Tiffany%27s_%28film%29>
> On Fri, Jan 15, 2010 at 1:47 PM, Eric Prud'hommeaux <eric@w3.org> wrote:
>
>> * Juan Sequeda <juanfederico@gmail.com> [2010-01-14 18:51-0500]
>> > Michael and all,
>> >
>> > I have a question about reusable identifiers.
>> >
>> > If I have my movie rental company relational database and I want to
>> expose
>> > it all as Linked Data. What should be the identifier for "Breakfast at
>> > Tiffany's?"
>> >
>> > http://dbpedia.org/resource/Breakfast_at_Tiffany%27s_%28film%29
>> > http://data.linkedmdb.org/resource/film/71
>> > okkam identifier for Breakfast at Tiffany's (if it exists)
>> >
>> > or should it be a
>> >
>> > http://myrentalstore.com/resource/film/123 owl:samesAs
>> > http://dbpedia.org/resource/Breakfast_at_Tiffany%27s_%28film%29
>>
>> While it's fabulous to use URLs for both unambiguity *and*
>> exploration, the two are in conflict in most publication scenarios.
>> IF you use dbpedia and *everyone* uses dbpedia, data integration
>> becomes trivial; people who used to write mashups can now just write
>> SPARQL queries.
>>
>> The downside is that you lose the appealing aspect of controlling what
>> content the user sees, which means, you don't get to pepper it with
>> links like <rent it> or <if you liked this, you'll also like...>.
>>
>> The fallback is to have myrentalstore links and some owl:sameAs. The
>> user sees what you want them to see, and sparql query authors have a
>> small additional burden of including the sameAs in their mashup query.
>> (You could have a SPARQL query translator that stuck sameAs in willy
>> nilly, but the cost of that query is much higher.)
>>
>> This problem is apparent in most LOD sites which are actually large
>> warehouses. One possible solution is to have a bit more protocol so
>> that when you start out using your generic RDF browser on
>> myrentalstore, you can follow a link to dbpedia and have the browser
>> do an extra query on the myrentalstore SPARQL server to supplement the
>> info. Another is to divide data from display:
>>  <p><a href="http://myrentalstore.com/resource/film/123">
>> http://dbpedia.org/resource/Breakfast_at_Tiffany%27s_%28film%29</a> a <a
>> href="http://myrentalstore.com/resource/Classics">
>> http://dbpedia.org/resource/Film_Classic</a> .</p>
>>
>> Most of these solutions have some drawbacks; time will tell what we
>> choose and what would should have chosen.
>>
>> > Audrey Hepburn, can be considered a well known entity with URIs in
>> dbpedia,
>> > freebase, etc. We know that Audrey Hepburn acted in Breakfast at
>> Tiffany's.
>> > So should I have my own URI for the movie and reuse an identifier for
>> Audrey
>> > Hepburn?
>> >
>> > I agree that we need to offer the possibility in the language to reuse
>> the
>> > identifiers, I'm just wondering what is the use case.
>> >
>> >
>> >
>> > Juan Sequeda, Ph.D Student
>> > Dept. of Computer Sciences
>> > The University of Texas at Austin
>> > www.juansequeda.com
>> > www.semanticwebaustin.org
>> >
>> >
>> > On Thu, Jan 14, 2010 at 5:48 AM, Michael Hausenblas <
>> > michael.hausenblas@deri.org> wrote:
>> >
>> > >
>> > > All,
>> > >
>> > > I've put my initial thoughts re the Linked Data aspects of R2RML on
>> our
>> > > Wiki
>> > > [1]. Please read, review & comment (preferably in the Wiki; saves us
>> all
>> > > time ;).
>> > >
>> > > Note that this will be the main discussion point for our upcoming
>> telco on
>> > > 2010-01-19.
>> > >
>> > > Cheers,
>> > >      Michael
>> > >
>> > > [1] http://www.w3.org/2001/sw/rdb2rdf/wiki/LinkedDataAspects
>> > >
>> > > --
>> > > Dr. Michael Hausenblas
>> > > LiDRC - Linked Data Research Centre
>> > > DERI - Digital Enterprise Research Institute
>> > > NUIG - National University of Ireland, Galway
>> > > Ireland, Europe
>> > > Tel. +353 91 495730
>> > > http://linkeddata.deri.ie/
>> > > http://sw-app.org/about.html
>> > >
>> > >
>> > >
>> > >
>>
>> --
>> -ericP
>>
>
>