OntoWeb SIG 2: Ontology Language Standards Heiner Stuckenschmidt Vrije Universiteit Amsterdam With contributions from: Ian Horrocks and Frank van Harmelen

Historical Perspective Ontology inference layer OIL (2000) –Developed by group of (largely) European researchers many of whom worked on OntoKnowledge project DAML ontology language DAML-ONT (2001) –Developed by group of (largely) US researchers working in DAML program Efforts merged in DAML+OIL (2002) –Further development by EU/US joint committee W3C Web Ontology group chartered ( ) –Tasked to develop W3C standard based on DAML+OIL

Goals of the SIG Coordinate cooperation, communication and participation in/with related initiatives and relevant standardization efforts and working groups. Forge additional links with other projects and with industry so as to further inform the language design process, and to stimulate the translation from industrial needs to technical and scientific problems. Disseminate the results of research and of standardization efforts, and to stimulate and support the transfer of research on ontology languages from academia to industry. Provide a forum for cooperation in the development of language extensions and the initiation of further standardization efforts.

Action Points Provide input to the DAML+OIL joint committee, the RDF core working group, and (later) the W3C working group on a web-ontology language. Provide usability reports on various web-ontology languages. Provide challenge problems for web-ontology languages. Establish contacts with other relevant communities (agent community not mentioned !?).

Meetings Heraklion, Crete, June 2001 –Identification of the state of the art –Decision about action points –Challenge problems Amsterdam, Netherlands, December 2001 –Report from standardization –Joint session with tool SIG –Creation of a wish list Cagliari, Sardinia, May 2002 –Workshop on rule markup Innsbruck, Austria, December 2002 –Review of OWL standardization documents

Progress on OWL Requirements document Language overview –High level overview of language features User guide and example ontology Language reference –Based on DAML+OIL language specification Abstract syntax and semantics –Ultimate normative reference Test cases –Designed to test implementation conformance

Semantic Layering Three language “layers” called: –OWL full Union of OWL DL and RDFS –Owl DL Restricted to DL/FOL fragment –OWL Lite Subset of OWL DL Syntactic layering Semantic layering –OWL DL semantics = OWL full semantics (within DL fragment) –OWL Lite semantics = OWL DL semantics (within Lite fragment) Full DL Lite

Related Activities Rule markup language –canonical Web language for rules using XML markup, formal semantics, and efficient implementations. DAML query language –formal language and protocol to use in conducting a query- answering dialogue using knowledge represented in DAML+OIL. DAML services –DAML-based Web Service Ontology (currently named DAML-S), as well as supporting tools and agent technology to enable automation of services on the Semantic Web

Perspectives for MAS Provide feedback on current standard –How well is OWL suited for specifying Ontologies in a multi-agent system ? Propose agent-related extensions –Are there specific language features that are essential for specifying the knowledge of an Agent ? Potential areas: –‘Trust’ layer –Services –Integration with other Languages Special SIG-meeting: Ontologies for MAS ?