- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Tue, 3 Aug 2004 12:55:52 -0400
- To: Farrukh Najmi <Farrukh.Najmi@Sun.COM>, Rob Shearer <Rob.Shearer@networkinference.com>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Farrukh, thanks for your response to Rob - I've gotten tired of reminding him and others that the DL methodology is only one of the ways OWL can be used (and in practice, it's not even the most common - most OWL out there falls in Full, not DL) - it also has the problem it is not yet scaleable to some of the largest Lite/DL ontologies out there, and these are precisely the ones I want to access via query instead of "document" (since the documents can get huge and take a long hours to download, parse and classify). Tools that will admit to the reality of the world out there and help people process it will be quite welcome -JH p.s. Note, this is nothing against using DL when appropriate, as in many of NI's business uses, but just to make it clear that DL is only one of many ways OWL is being used, and it CANNOT be the defining restriction for all use cases and applicability ... oops, I'm starting to get passionate and use uppercase - I'll stop now... At 10:26 -0400 8/3/04, Farrukh Najmi wrote: >Rob Shearer wrote: > >>Greetings, Farrukh! >> >>Apologies for not initiating contact myself. >> >>Your use case came up at the face-to-face, and I was curious whether >>there were alternative ways to achieve the results you were trying to >>get. >> >>You suggest a method of "query refinement" to select the elements of an >>ontology in which you're interested: first do a general query, then add >>a few more qualifying predicates, then add a few more, each time taking >>a look at the result set and figuring out what to add to prune out the >>results in which you're not interested. (Please correct the most >>offensive bits of this crude summary.) >> >>In traditional description logics systems, the process of "concept >>refinement" is most commonly implemented by traversing a concept >>taxonomy using not just "subclass"-style edges, but rather >>"direct-subclass" relationships. For example, a taxonomy of "Worker", >>"White-Collar Worker", and "Accountant" would include both "White-Collar >>Worker" and "Accountant" as subclasses of "Worker", however only >>"White-Collar Worker" would be a direct subclass. >> >>The common use pattern would be a user interested in "Worker", so the >>user asks for the direct subs of worker and finds that they are "White >>Collar", "Blue Collar", "Service", and "Military". He can then drill >>down on whichever of these he wishes, each time getting a fairly small >>and easily-consumed result set. This is usually much easier to manage >>than trying to figure out how to refine hundreds, thousands, or millions >>of results by hand somehow. >> >>Is any approach along these lines applicable to your use case? >I totally agree with sub-class refinement as the most common narrowing >technique. > >The use case envision the query to have zero or more parameters. Any one >of the parameters >MAY be a Concept in a taxonomy (or a class in an Ontology). > >This is implied but not stated in the use case as I was trying to have a >minimalistic >description that was easy to follow and conveyed the core use case. > >If you would like to propose a modified version to the use case text >send me a draft and >we can try and reach closure on the issue before the next DAWG meeting if >possible. > > >-- >Regards, >Farrukh -- Professor James Hendler http://www.cs.umd.edu/users/hendler Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742
Received on Tuesday, 3 August 2004 12:56:52 UTC