Structural and Role-Oriented Web Service Discovery with Taxonomies in OWL-S

In this paper, we describe and evaluate a Web service discovery framework using OWL-S advertisements, combined with the distinction between service and Web service of the WSMO Discovery Framework. More specifically, we follow the Web service discovery model, which is based on abstract and lightweight semantic Web service descriptions, using the Service Profile ontology of OWL-S. Our goal is to determine fast an initial set of candidate Web services for a specific request. This set can then be used in more fine-grained discovery approaches, based on richer Web service descriptions. Our Web service matchmaking algorithm extends object-based matching techniques used in Structural Case-based Reasoning, allowing 1) the retrieval of Web services not only based on subsumption relationships, but exploiting also the structural information of OWL ontologies and 2) the exploitation of Web services classification in Profile taxonomies, performing domain-dependent discovery. Furthermore, we describe how the typical paradigm of Profile input/output annotation with ontology concepts can be extended, allowing ontology roles to be considered as well. We have implemented our framework in the OWLS-SLR system, which we extensively evaluate and compare to the OWLS-MX matchmaker.