3 Adrian K. Clear Stephen Knox Juan Ye Lorcan Coyle Simon Dobson Paddy Nixon 2006 Pavel Shvaiko and Jérôme Euzenat and Alain Léger and Deborah L. McGuinness and Holger Wache Contexts and Ontologies: Theory, Practice and Applications Riva Del Garda, Italy CEUR Workshop Proceedings 210 20-25 28/08/2006 context, ontology, construct, pervasive computing, ubiquitous computing There is a commonly accepted need for contexts and ontologies to describe the vast amounts of data that are available to pervasive computing applications. Existing contexts and ontologies are either much generalised, very application specific, or inflexible. An integrated approach is required in which new concepts can be added and related to existing ones transparently. This paper describes a novel approach to the design of a set of contexts and ontologies for context-aware pervasive computing systems. It describes a Query Service, that lies between applications and contextual information, which complemented by the contexts and ontologies, offers a more powerful query answering service to application developers than is currently available.