- From: Bijan Parsia <bparsia@isr.umd.edu>
- Date: Fri, 13 Feb 2004 07:25:06 -0500
- To: Michael Lutz <m.lutz@uni-muenster.de>
- Cc: public-sws-ig@w3.org, Arnd Sahlmann <sahlmann@ifgi.uni-muenster.de>
On Feb 13, 2004, at 3:55 AM, Michael Lutz wrote: > as we did not get any responses to our first (lengthy) e-mail, here's > another (much shorter) try. Sorry, lots going on. > Reasoners like RACER are able to compute taxonomies between (OWL) > concepts (ontology classes). As OWL-S itself is an ontology of > services It's an ontology about services. Maybe of services if we consider the tripartite division of Atomic, Composite, and Simple, I suppose. What I meant is that we have no specific service types defined. > - how is it possible to reason about OWL-S service descriptions > (which are instances in that ontology) in order to derive taxonomies > of services? In Processes as Classes (PAC), there was the thought that of any two services, you could derive whether one was more general than the other by computing their subsumption relation. However, it's not clear that that's useful or that it's even common that services defined as concepts in this matter *would* tend to have interesting subsumption relations. This suggests that there was no loss, at least ;) In Processes as Instances (PAI), there is, I think, the intuition that "Service type" and "Service definition" are somewhat separate. If you want a hierarchy of service types based on the definitons, you need to define some classes which have as members those definitions. We have to define some classes just to get some of expressivity we want (e.g., that a class has exactly 3 inputs), so there should be emerging some (uninteresting?) class hierarchies). You might be able to generate classes by looking at these definitions and thus recapture some of the PAC thought, but I'm not sure this is beneficial. Reasoners with ABox capability (like Racer and Pellet) offer a number of services for dealing with indiviudals (Pellet, for example, offers sound and complete (if slow and a bit limited) conjunctive Abox query). I think there is the thought (:)) with PAI that this sort of thing is more useful in the arbitrary case. For any particular purpose, you should define your own classes of processes and do instance checking (or retrieval, or realization) against the fully classified class tree. I don't know if this answers your question, but even if not, I hope it helps :) What kinds of problems do you want to solve with such taxonomies? Cheers, Bijan Parsia.
Received on Friday, 13 February 2004 07:25:07 UTC