1. McGuinnessAAAI July 28, 2002 The Semantic Web (State of the art and implications for language processing) Deborah McGuinness Associate Director and Senior Research Scientist Knowledge Systems Laboratory Stanford University Stanford, CA USA dlm@ksl.stanford.edu http://www.ksl.stanford.edu/people/dlm

2. McGuinnessAAAI July 28, 2002 Outline Vision of the web today and tomorrow The key to tomorrow’s web is semantics Semantics on the web requires: –Language for encoding meaning (DAML+OIL, OWL) –Ontologies –Tools Conclusion and Pointers

3. McGuinnessAAAI July 28, 2002 Today: Rich Information Source for Human Manipulation/Interpretation Human

4. McGuinnessAAAI July 28, 2002 “I know what was input” Global documents and terms indexed and available for search Search engine interfaces Entire documents retrieved according to relevance (instead of answers) Human input, review, assimilation, integration, action, etc. Special purpose interfaces required for user friendly applications The web knows what was input but does little interpretation, manipulation, integration, and action. Analogous to a new assistant who is thorough yet lacks common sense, context, and adaptability

5. McGuinnessAAAI July 28, 2002 Tomorrow: Rich Information Source for Agent Manipulation/Interpretation HumanAgent

6. McGuinnessAAAI July 28, 2002 “I know what was meant” Understand term meaning and user background Interoperable (can translate between applications) Programmable (thus agent operational) Explainable (thus maintains context and can adapt) Capable of filtering (thus limiting display and human intervention requirements) Capable of executing services

7. McGuinnessAAAI July 28, 2002 Layer Cake Foundation

8. McGuinnessAAAI July 28, 2002 Stated goals of Semantic Web Define conventions for applications that exchange metadata on the Web Enable vocabulary semantics to be defined by communities of expertise, not W3C Provide for the fine-grained mixing of diverse metadata Making it cost-effective for people to effectively record their knowledge. Ultimate goal - the design of enabling technologies to support machine facilitated global knowledge exchange

9. McGuinnessAAAI July 28, 2002 Semantic Markup Languages such as OWL, DAML+OIL (http://www.w3.org/2001/sw/WebOnt/, http://www.daml.org) Encoding background info User modeling info Annotating web pages Annotating services thereby limiting needs for human disambiguation input, human interpretation, multiple answer display, translation assistance, agent assistance, adaptivity support, etc.) Ontologies DAML/OWL- enabled web pages

10. McGuinnessAAAI July 28, 2002 XML World Wide Web Consortium (W3C) standard Provides important solution to syntax problem and simple semantics and schemas: 555-17-1234 Now we can describe the meaning of words Many applications of XML appearing: –Geographic Markup Language (GML) –Extensible rights Markup Language (XrML) –Chemical Markup Language (CML) Problem: Limited semantics, limited ontology creation

11. McGuinnessAAAI July 28, 2002 DARPA Agent Markup Language http://www.daml.org/about.html Extends the vocabulary of XML and RDF/S Provides rich ontology representation language Language features chosen so language may have efficient implementations

12. McGuinnessAAAI July 28, 2002 DARPA DAML Program Began in August 2000 Kickoff meeting 19 Research groups supported Initial ontology language aims to extend XML, RDF/S, benefit from frames, benefit from principled KR systems like Description Logics DAML-ONT released in Oct. 2000 DAML+OIL released in March 2001

13. McGuinnessAAAI July 28, 2002 DAML Language Web Languages RDF/S XML DAML-ONT Formal Foundations Description Logics FACT, CLASSIC, DLP, … Frame Systems DAML+OIL (OWL) OIL

14. McGuinnessAAAI July 28, 2002 DAML+OIL -> W3C W3C Webont working group formed with DAML+OIL submission as starting point http://www.w3.org/Submission/2001/12/

15. McGuinnessAAAI July 28, 2002 W3C Web Ontology Working Group Web Ontology Working Group in the W3C Semantic Web Activity aimed at “extending the semantic reach of current XML and RDF meta- data efforts. “W3C Semantic Web Activity History –W3C Announcement in November 2001 - http://lists.w3.org/Archives/Public/www-rdf- logic/2001Nov/0000.html –Weekly teleconferences starting in November 2001

16. McGuinnessAAAI July 28, 2002 WEBONT catches on…. Includes over 50 members from over 30 organizations. –Industry including: Large companies such as Daimler Chrysler, EDS, Fujitsu, HP, IBM, Intel, Lucent, Nokia, Philips Electronics, Sun, Unisys, … Newer/smaller companies such as IVIS Group, Network Inference, Stilo Technology, Unicorn Solutions, … –Government and Not-For-Profits: Defense Information Systems Agency, Interoperability Technology Association for Information Processing, Japan (INTAP), Intelink Mgt Office, Mitre, … –Universities and Research Centers: University of Bristol, University of Maryland, University of Southamptom, Stanford University, … DFKI (German Research Center for Artificial Intelligence), Forschungszentrum Informatik –Invited Experts Well-known academics from non-W3C members

17. McGuinnessAAAI July 28, 2002 WEBONT cont. Quarterly Face to Face meetings in –Murray Hill: http://www.w3.org/2001/sw/WebOnt/ftf1.html –Amsterdam: http://www.w3.org/2001/sw/WebOnt/ftf2.html –Stanford: http://www.w3.org/2001/sw/WebOnt/ftf3.html –Upcoming – Bristol, and xxx Interesting Documents: –DAML+OIL submission – full spec with reference description, walkthrough, FOL and model theoretic semantics, http://www.w3.org/TR/daml+oil-reference –Use Case and requirements document: http://www.w3.org/TR/webont-req/

18. McGuinnessAAAI July 28, 2002 OWL Lite and OWL Feature Synopsis: http://www.w3.org/TR/owl-features/ Reference Description: http://www.w3.org/TR/owl-ref/ Abstract Syntax: http://www.w3.org/TR/owl-absyn/

19. McGuinnessAAAI July 28, 2002 OWL Lite Features RDF Schema Features –Class –rdf:Property –rdfs:subClassOf –rdfs:subPropertyOf –rdfs:domain –rdfs:range –Individual Equality and Inequality –sameClassAs –samePropertyAs –sameIndividualAs –differentIndividualFrom Restricted Cardinality –minCardinality (restricted to 0 or 1) –maxCardinality (restricted to 0 or 1) –cardinality (restricted to 0 or 1)

20. McGuinnessAAAI July 28, 2002 OWL Lite Features (cont) Property Characteristics –inverseOf –TransitiveProperty –SymmetricProperty –FunctionalProperty(unique) –InverseFunctionalProperty (unambiguous) –allValuesFrom (universal local range restrictions; previously toClass) –someValuesFrom (existential local range restrictions; previously hasClass) Datatypes –Following the decisions of RDF Core. Header Information –imports –Dublin Core Metadata –versionInfo

21. McGuinnessAAAI July 28, 2002 OWL Features Class Axioms –oneOf (enumerated classes) –disjointWith –sameClassAs applied to class expressions –rdfs:subClassOf applied to class expressions Boolean Combinations of Class Expressions –unionOf –intersectionOf –complementOf Arbitrary Cardinality –minCardinality –maxCardinality –cardinality Filler Information –hasValue Descriptions can include specific value information

22. McGuinnessAAAI July 28, 2002 Tools In order to take off, we need tools: http://www.daml.org/tools/ AnnotationOntology Translation BrowserPersistence CrawlerQuery Tools EditorRDMS Mapping Graph VisualizerReport Generation TransformationSearch Validator Ontology Analyzer Importer Ontology Editor Inference Engine Many are in research labs, but some in companies… Network Inference, Sandpiper, Ontoprise, ….

23. McGuinnessAAAI July 28, 2002 Ontologies Exploding Upper Level Ontologies Emerging: –UNSPSC, SUO, OpenCyc, OpenDirectory, TAP, … Specialized Ontologies Emerging –UMLS, NPC, Libraries –http://www.daml.org/ontologies/ –http://www.ksl.stanford.edu/ontolingua

24. McGuinnessAAAI July 28, 2002 Some Observations… Markup Languages are growing in acceptance and expressive power User base, tool base, ontology base growing Ontology-enhanced applications springing up (not just in ivory towers like FindUR, eCyc, …)

25. McGuinnessAAAI July 28, 2002 Simple Ontology-Enhanced Apps

26. McGuinnessAAAI July 28, 2002

27. McGuinnessAAAI July 28, 2002 Applied Semantics Applied Semantics uses a large scale ontology, or knowledge base of concepts and their relationships, to bring semantic understanding to the processing of unstructured information. Our software products and services improve the business processes for publishing, enterprise applications, and internet infrastructure markets by automating content tagging, categorization, and summarization for more effective information sharing and retrieval. Founded in 1998 Won Internet World Fall 1999 “Best of Show” for meaning-based search 40 employees Funding from: Zero Gravity, Ridgestone, others 50+ customers, including:

28. McGuinnessAAAI July 28, 2002 CIRCA in Publishing USERSUSERS USERSUSERS News Content CIRCA Technology Auto- Categorizer Metadata Creator Page Summarizer Proprietary Content Management System A major newspaper uses Auto-Categorizer by IPTC code (standard publishing taxonomy), Metadata Creator to generate meaningful thematic keywords, and Page Summarizer to summaries of varying lengths.

29. McGuinnessAAAI July 28, 2002 Conclusion/Discussion The Semantic Web is in its infancy today but is ready for applications Markup Language, Ontologies, and some tools are ready for use Hybrid applications may be the first to grow like ontology-enhanced search, ontology- enhanced knowledge capture, etc. Lets get together…..

30. McGuinnessAAAI July 28, 2002 Extras

31. McGuinnessAAAI July 28, 2002 What is an Ontology? Catalog/ ID General Logical constraints Terms/ glossary Thesauri “narrower term” relation Formal is-a Frames (properties) Informal is-a Formal instance Value Restrs. Disjointness, Inverse, part- of…

32. McGuinnessAAAI July 28, 2002 Some Pointers Ontologies Come of Age Paper: http://www.ksl.stanford.edu/people/dlm/papers/ ontologies-come-of-age-abstract.html http://www.ksl.stanford.edu/people/dlm/papers/ ontologies-come-of-age-abstract.html OWL: http://www.w3.org/TR/owl-features/, http://www.w3.org/TR/owl-ref/http://www.w3.org/TR/owl-features/ http://www.w3.org/TR/owl-ref/ DAML+OIL: http://www.daml.org/, http://www.w3.org/TR/daml+oil-referencehttp://www.daml.org/ http://www.w3.org/TR/daml+oil-reference

33. McGuinnessAAAI July 28, 2002 Contact Information dlm@ksl.stanford.edu www.ksl.stanford.edu/people/dlm