- From: Thomas Loertsch <loertsch.thomas@guj.de>
- Date: Wed, 15 Oct 2008 12:30:25 +0200
- To: Bernhard Schandl <bernhard.schandl@univie.ac.at>, Knud Hinnerk Möller <knud.moeller@deri.org>
- CC: Semantic Web <semantic-web@w3.org>
Thanks, using rdfs:subClassOf instead of owl:equivalentClass is a good point - fits very good with dc:title and hrecipe-title, since the former is the broader and more established term.. In other cases though I wouldn't necessarily assume that one concept is a sublass of another concept but that they are just equivalent. Which leads to using different properties for a similar purpose ("if you're interested in this, you might also be interested in that"). Or maybe owl:sameAs? The semantic web is always good for surprises where you first thought: "Ah, that one is easy!"... Cheers, Thomas On 15.10.08 08:07, "Bernhard Schandl" <bernhard.schandl@univie.ac.at> wrote: > > Hi Knud, > >>> That way a query for everything with a 'title' could automagically >>> sparql >>> the clearinghouse for every owl:equivalentClass of 'title' and add >>> those to >>> the original query. That's a scalable solution and it doesn't need >>> much >>> (actually none if I'm not mistaken) inferencing power either. >> >> That's an interesting idea. It would be interesting to find how this >> compares performance-wise to "ordinary" inferencing. > > We did this regularly in several applications, however we were not > using owl:equivalentClass but rdfs:subClassOf and rdfs:subPropertyOf; > and we applied this not only to labels but also to class instances: > > SELECT ?r ?l > WHERE > { > ?r rdf:type ?t . > ?t rdfs:subClassOf my:Something . > ?r ?p ?l . > ?p rdfs:subPropertyOf rdfs:label . > } > > This of course requires the full closure of subClassOf and > subPropertyOf relationships to be computed (but this can usually be > done once and then is persisted). We found this performs quite well in > comparison to fully fledged inferencing; however it has the drawback > that reasoning is encoded into applications, which one might find not > a nice solution. > > Best regards, > Bernhard > > . Thomas Lörtsch Living at Home Multi Media GmbH Redaktion Online .. Stubbenhuk 5 20459 Hamburg ... eMail: loertsch.thomas@guj.de
Received on Wednesday, 15 October 2008 10:31:21 UTC