Workshop at WWW2006, Edinburgh, UK, May 2006 Reasoning on the Web (RoW06) Invited talk by Ian Horrocks, University of Manchester Title: Ontology Reasoning: Why and How Abstract: The World Wide Web is phenomenally successful, and has made an unprecedented range of information and services available to an unprecedented number of users, but there is an urgent need for more intelligent applications that can better exploit these resources and prevent users being overwhelmed by their sheer volume. The goal of Semantic Web research is to facilitate the development of such applications by transforming the Web from a linked document repository into a distributed knowledge base and application platform. Ontologies will play a key role in this transformation by capturing knowledge that will enable applications to better understand Web accessible resources, and to use them more intelligently. This talk will discuss the contribution of basic research in knowledge representation to the design of OWL, a Semantic Web ontology language developed by the World Wide Web Consortium, and show how this design facilitates reasoning over ontologies; it will also explore why the developers and users of ontologies might want such reasoning.