OWL-S Reasoning -- Instances vs. Classes

Hi all,

we are a group of "geographers-turned-computer scientists" who are starting 
to get our heads around using OWL-S. Specifically we are planning to use 
OWL-S (Profiles) for service discovery (and later simple composition).

We have first experimented a little with "pure" OWL(-DL). We have modelled 
concepts as classes and used a reasoner (RACER) to compute taxonomies 
between those concepts. The resulting taxonomy can be used for service 
discovery (e.g. return all sub- or superclasses of the requested 
input/output classes to the requester).

OWL-S, however, models services as instances, which then refer through 
their IOPEs to OWL ontology classes. Our main questions in this context are:
How can we use those instances in reasoning for service discovery?
How does the service requester have to specify her request (class or instance)?
What is the role of more specific service types that can be derived from 
the generic OWL-S service profile? (Is it possible, e.g. to specify a 
specific service type (as a class) and then retrieve all service 
descriptions (instances) that are instances of that class?)

All this boild down to the question whether the service profile can  be 
used for service discovery as a whole or whether only its parts (mainly 
IOPEs) are to be parsed from the description and then be used in separate 
reasoning processes (e.g. computing one taxonomy for inputs, one for 
outputs etc. - this seems to be what is proposed in [1], for example)? If 
the latter is the case, i.e. if OWL-S only serves as a "fancy XML template" 
(I'm playing the devil's advocate here) what use is the OWL-S "overhead" 
for service discovery?

If you have any questions regarding mine, please don't hesitate to ask.
Any help with this (or pointers if this has already been discussed 
elsewhere) are greatly appreciated.

Michael Lutz


[1] KAWAMURA, T., J.-A. DE BLASIO, T. HASEGAWA, M. PAOLUCCI & K. SYCARA 
(2003): Preliminary Report of Public Experiment of Semantic Service 
Matchmaker with UDDI Business Registry.

Received on Monday, 9 February 2004 11:23:58 UTC