- From: Giovanni Tummarello <g.tummarello@gmail.com>
- Date: Tue, 23 Jun 2009 08:01:11 +0100
- To: martin.hepp@ebusiness-unibw.org
- Cc: Michael Hausenblas <michael.hausenblas@deri.org>, hepp@ebusiness-unibw.org, Richard Cyganiak <richard@cyganiak.de>, "Hepp, Martin" <mhepp@computer.org>, Hugh Glaser <hg@ecs.soton.ac.uk>, mark.birbeck@webbackplane.com, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "public-lod@w3.org" <public-lod@w3.org>
Just a remark about what we're doing in Sindice, for all who want to be indexed properly by us. we recursively dereference the properties that are used thus trying to obtain a closure over the description of the properties that are used. We also consider OWL imports. When the recursive fetching is computer, we apply RDFS + some owl reasoning (OWLIM being the final reasoner at the moment) and index it. We are currently working on a public validator where people can try their files and see the full chain of fetching/inference. Giovanni On Mon, Jun 22, 2009 at 7:42 PM, Martin Hepp (UniBW)<martin.hepp@ebusiness-unibw.org> wrote: > Hi Michael: > > (moving this to LOD public as suggested) > > General note: I am quite unhappy with a general movement in parts of the LOD > community to clash with the OWL world even when that is absolutely > unnecessary. It is just a bad engineering practice to break with existing > standards unless you can justify the side-effects. And this stubborn "i > don't care what the OWL specs says" pattern is silly, in particular if the > real motivation of many proponents of this approach is that they don't want > or cannot read the OWL specs. > > As for owl:imports: > > When importing an ontology by owl:imports, you commit to the whole formal > account of that ontology. If you just include an element from that ontology > by using it and hope that dereferencing will get the relevant formal account > in your model, you expose your model to randomness - you don't know what > subset of the formal account you will get served. Ontology modularization is > a pretty difficult task, and people use various heuristics for deciding what > to put in the subset being served for an element. There is no guarantee that > the fragment you get contains everything that you need. > > On the other hand - what is your pain with using RDFa in a way so that the > extracted RDF model is equivalent to the model from an RDF/XML or N3 > serialization? Why this absolutely arbitrary "we LOD guys don't like > owl:import ( we don't like OWL anyway, you know?), so we simply omit it" > behavior? > > It is just silly to break with established standards just for saving 1 - 2 > triples. > > Best > Martin > > Michael Hausenblas wrote: > > Martin, > > As an aside: I think I proposed already once to not have this discussion in > a private circle of 'randomly' selected people but rather in the appropriate > lists (rdfa public or public-lod). However, if you prefer to continue here, > we continue here, FWIW. > > > > In my opinion the owl:imports > stems from a time where people confused publishing on the Semantic Web with > firing up Protege and clicking around like wild. So, concluding, for me it > is not obvious to use owl:imports and I don't see *any* benefit from using > it. Not in RDF/XML and also not in RDFa ;) > > > you know that i sometimes appreciate your opinion ;-), > > > Yeah, same here :D > > > > ... but i think it is > pretty questionable to break with well-defined standards specifications > for just a matter of gut feeling and personal preference. > > > Ok, let me rephrase this. You, or whoever publishes RDFa can of course do > whatever she likes. Wanna use owl:imports? Fine. Don't wanna use it. Ok! > > The point I was trying to make (not very successfully, though): from a > linked data perspective (and basically this is what Richard and I try to > achieve here; offering good practices for linked data *in* RDFa) the usage > of owl:imports is, how to put it, not encouraged. > > So far I have not heard any convincing argument from you why one should use > it, but I'm happy and open to learn. > > Cheers, > Michael > > > > -- > -------------------------------------------------------------- > martin hepp > e-business & web science research group > universitaet der bundeswehr muenchen > > e-mail: mhepp@computer.org > phone: +49-(0)89-6004-4217 > fax: +49-(0)89-6004-4620 > www: http://www.unibw.de/ebusiness/ (group) > http://www.heppnetz.de/ (personal) > skype: mfhepp > twitter: mfhepp > > Check out the GoodRelations vocabulary for E-Commerce on the Web of Data! > ======================================================================== > > Webcast: > http://www.heppnetz.de/projects/goodrelations/webcast/ > > Talk at the Semantic Technology Conference 2009: > "Semantic Web-based E-Commerce: The GoodRelations Ontology" > http://tinyurl.com/semtech-hepp > > Tool for registering your business: > http://www.ebusiness-unibw.org/tools/goodrelations-annotator/ > > Overview article on Semantic Universe: > http://tinyurl.com/goodrelations-universe > > Project page and resources for developers: > http://purl.org/goodrelations/ > > Tutorial materials: > Tutorial at ESWC 2009: The Web of Data for E-Commerce in One Day: A Hands-on > Introduction to the GoodRelations Ontology, RDFa, and Yahoo! SearchMonkey > > http://www.ebusiness-unibw.org/wiki/GoodRelations_Tutorial_ESWC2009 > > > >
Received on Tuesday, 23 June 2009 07:02:03 UTC