Ontologies Come of Age Deborah L. McGuinness Associate Director and Senior Research Scientist Knowledge Systems Laboratory Stanford University Stanford, CA 94305 650-723-9770 [email protected].
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Ontologies Come of Age Deborah L. McGuinness Associate Director and Senior Research Scientist Knowledge Systems Laboratory Stanford University Stanford, CA 94305 650-723-9770 [email protected] What is an Ontology? Catalog/ ID Thesauri “narrower term” relation Terms/ glossary Formal taxonomy Term Hierarchy (e.g. Yahoo!) General Frames Description (properties) Logics Formal instance Value General Restrs. Logic *based on AAAI ’99 Ontologies panel – Gruninger, Lehmann, McGuinness, Uschold, Welty Updated by McGuinness, additional input from Gruninger, Uschold, and Rockmore June 18, 2003 McGuinness 1 General Nature of Descriptions class superclass number/card restrictions Roles/ properties value restrictions June 18, 2003 a WINE a LIQUID a POTABLE general categories grape: chardonnay, ... [>= 1] sugar-content: dry, sweet, off-dry color: red, white, rose price: a PRICE winery: a WINERY structured components grape dictates color (modulo skin) harvest time and sugar are related interconnections between parts McGuinness 2 Some uses of Ontologies Simple ontologies (taxonomies) provide: Controlled shared vocabulary (search engines, authors, users, databases, programs/agents all speak same language) Site Organization, Navigation Support, Expectation setting “Umbrella” Upper Level Structures (for extension e.g., UNSPSC) Browsing support (tagged structures such as Yahoo!) Search support (query expansion approaches such as FindUR, e-Cyc) Sense disambiguation (e.g., TAP) June 18, 2003 McGuinness 3 FindUR Architecture Content to Search: Research Site Technical Memorandum Calendars (Summit 2005, Research) Yellow Pages (Directory Westfield) Newspapers (Leader) Internal Sites (Rapid Prototyping) AT&T Solutions Worldnet Customer Care Medical Information Search Technology: User Interface: Content (Web Pages or Databases Classification CLASSIC Knowledge Representation System Search Engine Domain Domain Knowledge Knowledge GUI supporting browsing and selection Results (standard format) June 18, 2003 Content Results (domain specific) McGuinness Verity (and topic sets) Collaborative Topic Set Tool Verity SearchScript, Javascript, HTML, CGI, CLASSIC 4 June 18, 2003 McGuinness 5 June 18, 2003 McGuinness 6 June 18, 2003 McGuinness 7 June 18, 2003 McGuinness 8 Uses of Ontologies II Consistency Checking Completion Interoperability Support Support for validation and verification testing (e.g. http://ksl.stanford.edu/projects/DAML/chimaerajtp-cardinality-test1.daml ) Configuration support Structured, “surgical” comparative customized search Generalization / Specialization … Foundation for expansion and leverage June 18, 2003 McGuinness 9 KSL Wine Agent Semantic Web Integration Wine Agent receives a meal description and retrieves a selection of matching wines available on the Web, using an ensemble of emerging standards and tools: • DAML+OIL / OWL for representing a domain ontology of foods, wines, their properties, and relationships between them • JTP theorem prover for deriving appropriate pairings • DQL for querying a knowledge base consisting of the above • Inference Web for explaining and validating the response • [Web Services for interfacing with vendors] • Utilities for conducting and caching the above transactions June 18, 2003 McGuinness 10 June 18, 2003 McGuinness 11 Processing Given a description of a meal, Use DQL to state a premise (the meal) and query the knowledge base for a suggestion for a wine description or set of instances Use JTP Theorem Prover to deduce answers (and proofs) Use Inference Web to explain results (descriptions, instances, provenance, reasoning engines, etc.) Access relevant web sites (wine.com, wine commune, …) to access current information Use DAML-S for markup and protocol* http://www.ksl.stanford.edu/projects/wine/explanation.html June 18, 2003 McGuinness 12 June 18, 2003 McGuinness 13 June 18, 2003 McGuinness 14 Querying multiple online sources June 18, 2003 McGuinness 15 A Few Observations about Ontologies Simple ontologies can be built by non-experts Verity’s Topic Editor, Collaborative Topic Builder, GFP, Chimaera, Protégé, OIL-ED, etc. Ontologies can be semi-automatically generated from crawls of site such as yahoo!, amazon, excite, etc. Semi-structured sites can provide starting points Ontologies are exploding (business pull instead of technology push) e-commerce - MySimon, Amazon, Yahoo! Shopping, VerticalNet, … Controlled vocabularies (for the web) abound - SIC codes, UMLS, UNSPSC, Open Directory (DMOZ), Rosetta Net, SUMO Business interest expanding – ontology directors, business ontologies are becoming more complicated (roles, value restrictions, …), VC firm interested, Markup Languages growing XML, RDF, DAML, RuleML, xxML “Real” ontologies are becoming more central to applications Search companies moving towards them – Yahoo, recently Google June 18, 2003 McGuinness 16 June 18, 2003 McGuinness 17 June 18, 2003 McGuinness 18 Implications and Needs for Ontology-enhanced applications Ontology Language Syntax and Semantics (DAML+OIL, OWL) Upper Level/Core ontologies for reuse (Cyc, SUMO, CNS coalition, DAML-S…) Environments for Creation of Ontologies (Protégé, Sandpiper, Construct, OilEd, …) Environments for Maintenance of Ontologies (Chimaera, OntoBuilder, …) Reasoning Environments (Cerebra, Fact, JTP, Snark, …) Distributed explanation support (Inference Web) Training (Conceptual Modeling, reasoning usage, tutorials – OWL Guide, Ontologies 101, OWL Tutorial, …) June 18, 2003 McGuinness 19 Discussion/Conclusion • Ontologies are exploding; core of many applications • Business “pull” is driving ontology language tools and languages • New generation applications need more expressive ontologies and more back end reasoning • New generation users (the general public) need more support than previous users of KR&R systems • Distributed ontologies need more support: merging, analysis, explanation support, incompleteness techniques, versioning, etc. • Scale and distribution of the web force mind shift • Everyone is in the game – US Government (DARPA, NSF, NIST, ARDA…), EU, W3C, consortiums, business, … • Consulting and product companies are in the space (not just academics) This is THE time for ontology work!!! June 18, 2003 McGuinness 20 Pointers Selected Papers: - McGuinness. Ontologies come of age, 2003 - Das, Wei, McGuinness, Industrial Strength Ontology Evolution Environments, 2002. - Kendall, Dutra, McGuinness. Towards a Commercial Strength Ontology Development Environment, 2002. - McGuinness Description Logics Emerge from Ivory Towers, 2001. - McGuinness. Ontologies and Online Commerce, 2001. - McGuinness. Conceptual Modeling for Distributed Ontology Environments, 2000. - McGuinness, Fikes, Rice, Wilder. An Environment for Merging and Testing Large Ontologies, 2000. - Brachman, Borgida, McGuinness, Patel-Schneider. Knowledge Representation meets Reality, 1999. - McGuinness. Ontological Issues for Knowledge-Enhanced Search, 1998. - McGuinness and Wright. Conceptual Modeling for Configuration, 1998. Selected Tutorials: -Smith, Welty, McGuinness. OWL Web Ontology Language Guide, 2003. -Noy, McGuinness. Ontology Development 101: A Guide to Creating your First Ontology. 2001. - Brachman, McGuinness, Resnick, Borgida. How and When to Use a KL-ONE-like System, 1991. Languages, Environments, Software: - OWL - http://www.w3.org/TR/owl-features/ , http://www.w3.org/TR/owl-guide/ - DAML+OIL: http://www.daml.org/ - Inference Web - http://www.ksl.stanford.edu/software/iw/ - Chimaera - http://www.ksl.stanford.edu/software/chimaera/ - FindUR - http://www.research.att.com/people/~dlm/findur/ - TAP – http://tap.stanford.edu/ - DQL - http://www.ksl.stanford.edu/projects/dql/ June 18, 2003 McGuinness 21 Extras June 18, 2003 McGuinness 22 <rdfs:Class rdf:ID="BLAND-FISH-COURSE"> <daml:intersectionOf rdf:parseType="daml:collection"> <rdfs:Class rdf:about="#MEAL-COURSE"/> <daml:Restriction> <daml:onProperty rdf:resource="#FOOD"/> <daml:toClass rdf:resource="#BLAND-FISH"/> </daml:Restriction> </daml:intersectionOf> <rdfs:subClassOf rdf:resource="#DRINK-HAS-DELICATE-FLAVOR-RESTRICTION"/> </rdfs:Class> <rdfs:Class rdf:ID="BLAND-FISH"> <rdfs:subClassOf rdf:resource="#FISH"/> <daml:disjointWith rdf:resource="#NON-BLAND-FISH"/> </rdfs:Class> <rdf:Description rdf:ID="FLOUNDER"> <rdf:type rdf:resource="#BLAND-FISH"/> </rdf:Description> <rdfs:Class rdf:ID="CHARDONNAY"> <rdfs:subClassOf rdf:resource="#WHITE-COLOR-RESTRICTION"/> <rdfs:subClassOf rdf:resource="#MEDIUM-OR-FULL-BODY-RESTRICTION"/> <rdfs:subClassOf rdf:resource="#MODERATE-OR-STRONG-FLAVOR-RESTRICTION"/> […] </rdfs:Class> <rdf:Description rdf:ID="BANCROFT-CHARDONNAY"> <rdf:type rdf:resource="#CHARDONNAY"/> <REGION rdf:resource="#NAPA"/> <MAKER rdf:resource="#BANCROFT"/> <SUGAR rdf:resource="#DRY"/> […] </rdf:Description> June 18, 2003 McGuinness 23 DAML/OWL Language •Extends vocabulary of XML and RDF/S •Rich ontology representation language •Language features chosen for efficient implementations Frame Systems Web Languages RDF/S XML DAML-ONT DAML+OIL OWL OIL Formal Foundations Description Logics FACT, CLASSIC, DLP, … June 18, 2003 McGuinness 24 Issues Collaboration among distributed teams Interconnectivity with many systems/standards Analysis and diagnosis Scale Versioning Security Ease of use Diverse training levels / user support Presentation style Lifecycle Extensibility June 18, 2003 McGuinness 25 Services Ontologies DAML-S http://www.daml.org/services/ publication references ontology specifications examples A few interesting projects using DAML-S: MyGrid: (http://mygrid.man.ac.uk) AgentCities (http://www.agentcities.org) Services composer (http://www.mindswap.org/~evren/composer/) June 18, 2003 McGuinness 26 General Nature of Descriptions a WINE June 18, 2003 a LIQUID a POTABLE general categories grape: chardonnay, ... [>= 1] sugar-content: dry, sweet, off-dry color: red, white, rose price: a PRICE winery: a WINERY structured components grape dictates color (modulo skin) harvest time and sugar are related interconnections between parts McGuinness 27 SUMO Available in KIF (first order logic), DAML, LOOM and XML May be used without fee for any purpose (including for profit) Mapped by hand to 100,000 synsets of WordNet lexicon Validated with formal theorem proving 52 publicly released versions created over two years (approximately 1,000 concepts, 4000 assertions, and 750 rules so far) Specialized with dozens of free domain ontologies In use by companies, universities and government around the world Acadmica Sinica – Taiwan, U Arizona, lookwayup.com, NIST etc Available at http://ontology.teknowledge.com June 18, 2003 McGuinness 28 Chimaera – A Ontology Environment Tool An interactive web-based tool aimed at supporting: •Ontology analysis (correctness, completeness, style, …) •Merging of ontological terms from varied sources •Maintaining ontologies over time •Validation of input • Features: multiple I/O languages, loading and merging into multiple namespaces, collaborative distributed environment support, integrated browsing/editing environment, extensible diagnostic rule language • Used in commercial and academic environments; used in HORUS to support counter-terrorism ontology generation • Available as a hosted service from www-ksl-svc.stanford.edu • Information: www.ksl.stanford.edu/software/chimaera June 18, 2003 McGuinness 29 Layer Cake Foundation June 18, 2003 McGuinness 30 June 18, 2003 McGuinness 31 June 18, 2003 McGuinness 32 Some Pointers Ontologies Come of Age Paper: http://www.ksl.stanford.edu/people/dlm/papers/ontolo gies-come-of-age-abstract.html Ontologies and Online Commerce Paper: http://www.ksl.stanford.edu/people/dlm/papers/ontolo gies-and-online-commerce-abstract.html DAML+OIL: http://www.daml.org/ WEBONT: http://www.w3.org/2001/sw/WebOnt/ OWL: http://www.w3.org/TR/owl-features/ June 18, 2003 McGuinness 33 E-Commerce Search (starting point Forrester Research modified by McGuinness) Ask Queries - multiple search interfaces (surgical shoppers, advice seekers, window shoppers) - set user expectations (interactive query refinement) - anticipate anomalies Get Answers - basic information (multiple sorts, filtering, structuring) - modify results (user defined parameters for refining, user profile info, narrow query, broaden query, disambiguate query) - suggest alternatives (suggest other comparable products even from competitor’s sites) Make Decisions - manipulate results (enable side by side comparison) - dive deeper (provide additional info, multimedia, other views) - take action (buy) McGuinness 34 June 18, 2003 The Need For KB Analysis Large-scale knowledge repositories will necessarily contain KBs produced by multiple authors in multiple settings KBs for applications will typically be built by assembling and extending multiple modular KBs from repositories that may not be consistent KBs developed by multiple authors will frequently Express overlapping knowledge in different, possibly contradictory ways Use differing assumptions and styles For such KBs to be used as building blocks They must be reviewed for appropriateness and “correctness” That is, they must be analyzed June 18, 2003 McGuinness 35 Our KB Analysis Task Review KBs that: Were developed using differing standards May be syntactically but not semantically validated May use differing modeling representations Produce KB logs (in interactive environments) June 18, 2003 Identify provable problems Suggest possible problems in style and/or modeling Are extensible by being user programmable McGuinness 36