OntoWeb SIG 2: Ontology Language Standards Heiner Stuckenschmidt Vrije Universiteit Amsterdam

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

2. 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 (2002-2003) • Tasked to develop W3C standard based on DAML+OIL

3. 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 projectsand 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.

4. 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 !?).

5. 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

6. 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

7. 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

8. 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

9. 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 ?