Jürgen Jakobitsch wrote: > hi, > > results might sometimes also be correct but clinton-like (misleading) > > consider the fact, that sparqling for skos:broaderTransitive does not include > the direct skos:broader. > > for example : > > - conceptA skos:broader conceptB > - conceptB skos:broader conceptC > - conceptC skos:broader conceptD > > sparql for skos:broader of conceptA => includes conceptB (and nothing else) > sparql for skos:broaderTranisitive of conceptA => includes conceptC, conceptD > (but not conceptA) > sparql for skos:broader of conceptC => includes conceptD (and nothing else) > sparql for skos:broaderTransitive of conceptC => includes emptiness > > if you would like the whole chain of broaders you would need to use > skos:broader UNION skos:broaderTransitive > > analog for narrowers > > but there's definitly something wrong with the broaderTransitive reasoning. > > some further down wrote something broaderTransitive subPropertyOf broader : > > PLEASE take care skos:broader is a subPropertyOf skos:broaderTransitive !! > > wkr www.turnguard.com > > > > > ----- Original Message ----- > From: "Alexandre Passant" <alexandre.pass...@deri.org> > To: "Kingsley Idehen" <kide...@openlinksw.com> > Cc: public-...@w3.org, "Antoine Isaac" <ais...@few.vu.nl>, > pedantic-...@googlegroups.com, dbpedia-discussion@lists.sourceforge.net > Sent: Thursday, October 8, 2009 1:17:41 PM GMT -05:00 US/Canada Eastern > Subject: Re: [Dbpedia-discussion] DBpedia SPARQL Endpoint and Transitive > Queries > > Hi, > > On 8 Oct 2009, at 16:54, Kingsley Idehen wrote: > > >> Antoine Isaac wrote: >> >>> Alexandre Passant a écrit : >>> >>>> Hi, >>>> >>>> On 8 Oct 2009, at 16:09, Kingsley Idehen wrote: >>>> >>>> >>>>> All, >>>>> >>>>> The intersection of Leigh Dodds SPARQL extensions survey [1], >>>>> imminent official release of Virtuoso 6.0 (DBpedia basic and Live >>>>> already use this, ditto LOD Cache, and B3S public endpoints), and >>>>> an old post by Bernard Vatant re. skos:broader, has lead to this >>>>> simple, but powerful example of Virtuoso's Transitive Option >>>>> extension for SPARQL : >>>>> >>>>> #Transitive Option Off >>>>> >>>>> PREFIX p: <http://dbpedia.org/property/> >>>>> PREFIX dbpedia: <http://dbpedia.org/resource/> >>>>> PREFIX category: <http://dbpedia.org/resource/Category:> >>>>> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> >>>>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> >>>>> PREFIX geo: <http://www.georss.org/georss/> >>>>> >>>>> SELECT DISTINCT ?m ?n ?p ?d >>>>> WHERE { >>>>> ?m rdfs:label ?n. >>>>> ?m skos:subject ?c. >>>>> ?c skos:broader category:Churches_in_Paris. >>>>> ?m p:abstract ?d. >>>>> ?m geo:point ?p >>>>> FILTER ( lang(?n) = "fr" ) >>>>> FILTER ( lang(?d) = "fr" ) >>>>> } >>>>> >>>>> #Transitive Option On >>>>> >>>>> PREFIX p: <http://dbpedia.org/property/> >>>>> PREFIX dbpedia: <http://dbpedia.org/resource/> >>>>> PREFIX category: <http://dbpedia.org/resource/Category:> >>>>> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> >>>>> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> >>>>> PREFIX geo: <http://www.georss.org/georss/> >>>>> >>>>> SELECT DISTINCT ?m ?n ?p ?d >>>>> WHERE { >>>>> ?m rdfs:label ?n. >>>>> ?m skos:subject ?c. >>>>> ?c skos:broader category:Churches_in_Paris OPTION (TRANSITIVE). >>>>> ?m p:abstract ?d. >>>>> ?m geo:point ?p >>>>> FILTER ( lang(?n) = "fr" ) >>>>> FILTER ( lang(?d) = "fr" ) >>>>> } >>>>> >>>>> >>>>> >>>> As skos:broader is not transitive [1] but its superproperty >>>> skos:broaderTransitive is, shouldn't the second query be >>>> >>>> ?c skos:broaderTransitive category:Churches_in_Paris OPTION >>>> (TRANSITIVE). >>>> >>>> Best, >>>> >>>> Alex. >>>> >>>> [1] http://www.w3.org/TR/2009/REC-skos-reference-20090818/#L2413 >>>> >>> +1. Also, skos:subject is not in the recommendation... >>> >> Fine, but what happens when the data in question already has such >> triples? Try this against DBpedia: >> >> PREFIX p: <http://dbpedia.org/property/> >> PREFIX dbpedia: <http://dbpedia.org/resource/> >> PREFIX category: <http://dbpedia.org/resource/Category:> >> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> >> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> >> PREFIX geo: <http://www.georss.org/georss/> >> >> SELECT DISTINCT ?m ?n ?p ?d >> WHERE { >> ?m rdfs:label ?n. >> ?m skos:subject ?c. >> ?c skos:broaderTransitive category:Churches_in_Paris option >> (transitive) . >> ?m p:abstract ?d. >> ?m geo:point ?p >> FILTER ( lang(?n) = "fr" ) >> FILTER ( lang(?d) = "fr" ) >> } >> >> You will have an empty result-set. Again, this is the point Bernard >> Vatant made in his post a long time ago. >> > > So there is something wrong in the current inference done in DBPedia. > Indeed, that query lists one result > > PREFIX p: <http://dbpedia.org/property/> > PREFIX dbpedia: <http://dbpedia.org/resource/> > PREFIX category: <http://dbpedia.org/resource/Category:> > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX skos: <http://www.w3.org/2004/02/skos/core#> > PREFIX geo: <http://www.georss.org/georss/> > > SELECT DISTINCT ?m ?n ?p ?d > WHERE { > ?m rdfs:label ?n. > ?m skos:subject ?c. > ?c skos:broader category:Churches_in_Paris . > ?m p:abstract ?d. > ?m geo:point ?p > FILTER ( lang(?n) = "fr" ) > FILTER ( lang(?d) = "fr" ) > } > > But the following one list none > > PREFIX p: <http://dbpedia.org/property/> > PREFIX dbpedia: <http://dbpedia.org/resource/> > PREFIX category: <http://dbpedia.org/resource/Category:> > PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> > PREFIX skos: <http://www.w3.org/2004/02/skos/core#> > PREFIX geo: <http://www.georss.org/georss/> > > SELECT DISTINCT ?m ?n ?p ?d > WHERE { > ?m rdfs:label ?n. > ?m skos:subject ?c. > ?c skos:broaderTransitive category:Churches_in_Paris . > ?m p:abstract ?d. > ?m geo:point ?p > FILTER ( lang(?n) = "fr" ) > FILTER ( lang(?d) = "fr" ) > } > > However, skos:broaderTransitive is a superproperty of skos:broader, so > you should get at least the result of the first query included here. > Then, the query you mentioned earlier (using option (transitive) with > skos:broaderTransitive) should not give an empty set - and everything > work fine. > > Thanks, > > Alex. > > BTW, do you have a link to Bernard's post ? > > >> Ultimate solution: make an inference rule that asserts: >> <skos:broaderTransitive> owl:subPropertyOf <skos:broader> (or make a >> context rule from the entire skos ontology), and you will then have >> the revised query return data for those databases that have used >> skos:broader to build their concept scheme structure (assuming you >> apply the inference rule pragma). Otherwise, If your store has >> skos:broaderTransitive data, then just change the query :-) >> > > >> Kingsley >> >>> Best, >>> >>> Antoine >>> >>> >>> >> -- >> >> >> Regards, >> >> Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen >> President & CEO OpenLink Software Web: http://www.openlinksw.com >> >> >> >> >> > > -- > Dr. Alexandre Passant > Digital Enterprise Research Institute > National University of Ireland, Galway > :me owl:sameAs <http://apassant.net/alex> . > > > > > > > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > Dbpedia-discussion mailing list > Dbpedia-discussion@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > Dbpedia-discussion mailing list > Dbpedia-discussion@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion > All,
## Rule PREFIX skos: <http://www.w3.org/2004/02/skos/core#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> INSERT INTO GRAPH <urn:rules.skos> { skos:broader rdfs:subPropertyOf skos:broaderTransitive . skos:narrower rdfs:subPropertyOf skos:narrowerTransitive}; ## Virtuoso SQL for associating rule with specific context graph ## Execute via ISQL interface (Conductor or CommandLine variants) rdfs_rule_set ('skos-trans', 'urn:rules.skos'); ## Actual Query that uses a Context Rule to handle Instance data being skos:broader based DEFINE input:inference "skos-trans" PREFIX p: <http://dbpedia.org/property/> PREFIX dbpedia: <http://dbpedia.org/resource/> PREFIX category: <http://dbpedia.org/resource/Category:> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> PREFIX geo: <http://www.georss.org/georss/> SELECT DISTINCT ?m ?n ?p ?d WHERE { ?m rdfs:label ?n. ?m skos:subject ?c. ?c skos:broaderTransitive category:Churches_in_Paris option (transitive) . ?m p:abstract ?d. ?m geo:point ?p FILTER ( lang(?n) = "fr" ) FILTER ( lang(?d) = "fr" ) } ## Execute the above against the DBpedia SPARQL endpoint will return data, now that context rule has been created and pragma is in the SPARQL -- Regards, Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen President & CEO OpenLink Software Web: http://www.openlinksw.com ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Dbpedia-discussion mailing list Dbpedia-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
