Bridging the Paradigm Gap with Rules for OWL
Pascal Hitzler, Jürgen Angele, Boris Motik, Rudi Studer · 2005
Accelerated by the vision of the semantic web, semantic technologies have recently made significant advances. The underlying methods and paradigms are already being transferred to adjacent areas of research in artificial intelligence, knowledge management, and elsewhere. Textbooks explaining the foundations have appeared. Large national and international projects on the topic are under way. The technology received a crucial impulse when the Web Ontology Language OWL became a W3C recommendation in 2004. It is already being perceived as a basic knowledge representation language with potential which goes far beyond the semantic web use case. At the same time, it is apparent that OWL needs to be extended with additional expressive features in order to become applicable and useful in many domains. Corresponding efforts are being pursued with frenzy by research institutions and industry. These efforts are being aided substantially by the fact that OWL is based on sound logical foundations as it can be understood as a well-understood decidable albeit very expressive fragment of first order logic. The need for an extension of OWL by rules has been known since the beginning. Indeed, the rule-based ontology representation language F-Logic [6, 1] is being used widely where a rule-based approach appears to be more feasible. As an example, we mention the HALO project 1 by Vulcan Inc. 2 whose ultimate goal is the creation of a “digital Aristotle”, an expert tutor in a wide variety of subjects, with deep reasoning abilities. The initial The first named author acknowledges support by the European Union under the KnowledgeWeb Network of Excellence, and by the German Federal Ministry for Education and Research, BMBF, under the SmartWeb project. The third named author acknowledges support by the European Union under the DIP project.