Ontological Reasoning and Abductive Logic Programming for Service Discovery and Contracting

The Service Oriented Architecture paradigm, and its implementation based on Web Services, have been the object of an intense research and standardization activity. One of the most challenging open research issues is the discovery of Web Services on the base of the functionality they offer. Several proposals, including WSMO and OWL-S, rely on Semantic Web technologies to enrich service descriptions with semantic information about the offered functionalities. Current solutions however mainly focus on ontological aspects. In this paper we focus instead on aspects related to web service interaction. We present an application framework that addresses the service discovery problem by accommodating both the ontological and the interaction perspectives. It does so by reasoning with a number of ingredients that specify how web services and users interact: web service semantic descriptions and declarative rules, and user goals, parameters and policies. The aim of our framework is to discover and propose to user services which (1) ontologically fulfill the requested functionalities, and (2) allow the user to interact with the services and possibly achieve her goals, without violating her policies.