Copyright © 1997 Pangea Systems, Inc. All rights reserved. OIL: A Slick way to represent knowledge on the web Carole Goble, Ian Horrocks University of Manchester and The OIL Consortium

Copyright © 1998 Pangea Systems, Inc. All rights reserved. Describing and Exchanging Ontologies To reuse an ontology we need to share it with others in the community Exchanging ontologies requires a language with:  common syntax  clear and explicit shared meaning Tools for parsing, delivery, visualising etc

Copyright © 1998 Pangea Systems, Inc. All rights reserved. XOL eXtensible Ontology Language XML markup Frame based Based on OKBC-Lite iXOL by KSL Stanford

Copyright © 1998 Pangea Systems, Inc. All rights reserved. Frames: modelling primitives, OKBC-Lite Description Logics: formal semantics & Automated reasoning support Web languages: XML & RDF based syntax OIL OIL: Ontology Inference Layer The language formally known as Ontology Interchange language Extends XOL (some current restrictions) Gives a semantics to RDF-Schema A knowledge representation language and inference mechanism for the web

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL: Ontology Metadata (Dublin Core) Ontology-container title “macromolecule fragment” creator “robert stevens” subject “macromolecule generic ontology” description “example for a tutorial” description.release “1.0” publisher “R Stevens” type “ontology” formal “pseudo-xml” identifier “ source “ language “OIL” language “en-uk” relation.haspart “

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL primitive ontology definitions slot-def has-backbone inverse is-backbone-of slot-def part-of inverse is -part-of properties transitive class-def rna subclass-of nucleic-acid slot-constraint has-backbone value-type ribophosphate class-def ribophosphate class-def deoxyribophosphate subclass-of NOT ribophosphate

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL defined ontology definitions class-def defined dna subclass-of nucleic-acid slot-constraint has-backbone value-type deoxyribophosphate class-def dna subclass-of NOT rna class-def defined catalyst subclass-of macromolecule slot-constraint promotes has-value reaction class-def defined enzyme subclass-of protein, catalyst

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL defined ontology definitions class-def defined mitochondrial subclass of location slot-constraint cellularlocation cardinality 1 ((has-value mitochondrion) OR (slot-constraint part-of has-value mitochondrion)) class-def defined succinate-dehydrogenase subclass of enzyme slot-constraint promotes value-type oxidation slot-constraint cellularlocation cardinality 1 (has-value (slot-constraint part-of has-value mitochondrion)

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL in XML OIL has a DTD, an XML Schema and a mapping to RDF-Schema. See web site for details

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL Extensibility Model Concrete domains (integers, strings) are on their way to the core... Decidable Core Default Reasoning Rules/ Axioms Instances in Class Definitions Limited 2nd order expressivity

Copyright © 1998 Pangea Systems, Inc. All rights reserved. OIL Directions Tools:  FaCT reasoner with CORBA IDL  OilEd: Protégé II + FaCT reasoner  Chimaera  OntoEdit DARPA Agent Markup Language initiative  OIL will be the language likely to be adopted W3C  Collaborators on DAML  OIL likely for Semantic Web language Other projects:  Semantic Web projects (  OntoWeb Network of Excellence  SemanticWeb IST EU Proposal

Copyright © 1998 Pangea Systems, Inc. All rights reserved. Tim Berners-Lee’s Semantic Web “My definition of the Web is a universe of network- accessible information,  a means of human-to-human communication, and  a space in which software agents can, though access to a vast amount of everything which is society, science and its problems, become tools to work with us.” Web Architecture from 50,000 feet From Machine Readable to Machine understandable

Copyright © 1998 Pangea Systems, Inc. All rights reserved. The OIL Acknowledged Contributors Ian Horrock and Carole Goble, Department of Computer Science, University of Manchester, UK Dieter Fensel, Michel Klein, Frank van Harmelen, Ying Ding, Rainer Faulstich, Borys Omelayenko and Hans Akkermans, Vrije Universiteit Amsterdam, Nederland Jeen Broekstra, Frank van Harmelen, Jos van der Meer and Christiaan Fluit, Aidministrator, Nederland Guus Schreiber, SWI, University of Amsterdam, Nederland Enrico Motta, Knowledge Media Institute, Open University, UK Deborah McGuinness, Stefan Decker, Stanford University, USA Michael Erdmann, Stefan Staab, Alexander Maedche and Rudi Studer, Institute AIFB, University of Karlsruhe, Germany Peter Karp, SRI International's Artificial Intelligence Center, USA Monika Crubezy, Stefan Decker, William Grosso, and Mark Musen, Knowledge Modeling Group at Stanford Medical Informatics, Stanford University, USA Heiner Stuckenschmidt, University of Bremen, Germany Robin McEntire, SmithKline Beecham John Davis, John Hughes, Uwe Krohn, British Telecom Ulrich Reimer, Martin Staudt, Swiss Life Robert Engels, CognIT Bernt A. Bremdal and Fredrik Ygge, EnerSearch