Regenerative medicine: Current therapies and future directions
The Semantic Web (Current State and Directions)
description
Transcript of The Semantic Web (Current State and Directions)
McGuinness NSF/NCAR October 30, 2002
The Semantic Web (Current State and Directions)
Deborah McGuinness
Associate Director and Senior Research Scientist
Knowledge Systems Laboratory
Stanford University
Stanford, CA USA
http://www.ksl.stanford.edu/people/dlm
McGuinness NSF/NCAR October 30, 2002
Outline
• Web: today and tomorrow– The key to tomorrow’s web is semantics
• Semantics on the web requires:– Language for encoding meaning (XML, RDF/S ->
DAML+OIL, OWL)
– Ontologies (Term descriptions and their interrelationships)
– Tools
• Conclusion and Pointers
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Today: Rich Information Source for Human Manipulation/Interpretation
Human
Human
Human
Human
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“I know what was input”
The web knows what text was input (and is great at information dissemination) but does little interpretation, manipulation, integration, and action.
Analogous to a new assistant who is thorough yet lacks common sense, context, adaptability, and the ability to interpret for you
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Tomorrow: Rich Information Source for Agent Manipulation/Interpretation
Human
Agent
Agent
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“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
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Layer Cake Foundation
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Semantic Markup In languages such as OWL, DAML+OIL(http://www.w3.org/2001/sw/WebOnt/, http://www.daml.org), we capture• Background info• User modeling infofor• Annotating web pages (man/automatically)• 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
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DAML/OWL Language
Web LanguagesRDF/SXML
DAML-ONT
Formal FoundationsDescription Logics
FACT, CLASSIC, DLP, …
Frame Systems
DAML+OILOWL
OIL
•Extends vocabulary of XML and RDF/S•Rich ontology representation language•Language features chosen for efficient implementations
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W3C WEBONT catches on…. • Includes over 50 members from over 30 international organizations.
– Industry including:• Large companies such as Daimler Chrysler, EDS, Fujitsu, HP, IBM, Intel,
Lucent, Motorola, 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,
• ARDA, CIA, DARPA, DIA, NCI, NIH, NIST, NSF, …– Universities and Research Centers:
• Stanford University, University of Bristol, University of Maryland, University of Southamptom, …
• DFKI (German Research Center for Artificial Intelligence), Forschungszentrum Informatik
– Invited Experts • Well-known academics from non-W3C members
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OWL Lite Features • RDF Schema Features
– Class, rdfs:subClassOf , Individual – rdf:Property, rdfs:subPropertyOf – rdfs:domain , rdfs:range
• Equality and Inequality– sameClassAs , samePropertyAs , sameIndividualAs – differentIndividualFrom
• Restricted Cardinality – minCardinality, maxCardinality (restricted to 0 or 1) – cardinality (restricted to 0 or 1)
• Property Characteristics– inverseOf , TransitiveProperty , SymmetricProperty – FunctionalProperty(unique) , InverseFunctionalProperty– allValuesFrom, someValuesFrom (universal and existential local range
restrictions)• Datatypes
– Following the decisions of RDF Core. • Header Information
– imports , Dublin Core Metadata , versionInfo
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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
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OWL Lite and OWL
• Feature Synopsis:
http://www.w3.org/TR/owl-features/• Guide:
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/
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Do I have to build the ontologies myself? Maybe not….Ontologies (suitable for reuse) are exploding
• Upper Level Ontologies– UNSPSC, SUO, OpenCyc, OpenDirectory, TAP, …
• Specialized Ontologies– UMLS, SNOMED, GO, CIA World Fact book, DAML-S…, even
vc’s – Vulcan,…
• Ontology Libraries– http://www.daml.org/ontologies/– http://www.ksl.stanford.edu/ontolingua
• “Advisory” bodies– Semantic Web Science Foundation, NIST, Ontology.org, …
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Ontologies in most areas … including the environment
Quick web search yielded:• Semantic Web for Earth and Environmental Terminology –JPL.
http://oceanesip.jpl.nasa.gov/sweet
• National Institute for environmental eScience – Cambridge - http://www.niees.ac.uk/
• Gene Ontology – “dynamic controlled vocabulary that can be applied
to all organisms” http://www.geneontology.org/
• Design and Creation of Ontologies for Environmental Information Retrieval- Telecordia - http://sern.ucalgary.ca/KSI/KAW/KAW99/papers/Kashyap1/kashyap.pdf
• Ontologies of environmental applications for a digital library of scientific collections - http://dlforum.external.forth.gr:8080/papers/EnviroInfo.pdf
• Waste water ontology – decision support for wastewater treatment processes - http://citeseer.nj.nec.com/ceccaroni00wawo.html
• ... Many others …
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Tools
Tools developing: http://www.daml.org/tools/
Annotation Ontology TranslationBrowser PersistenceCrawler Query ToolsEditor RDMS MappingGraph Visualizer Report GenerationTransformation Search Validator Ontology AnalyzerImporter Ontology EditorInference Engine Merging
Many are in research labs, but companies emerging and lasting…Network Inference, Sandpiper, Ontoprise, AppliedSemantics, Sentius, ….
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Conclusion/Discussion• The Semantic Web is in its infancy today but is ready for
applications• Markup languages, ontologies, and some tools are ready
for use• Specialized tools are buildable/usable today• Semantic web can be leveraged to support: (items from
Tim, Margaret, Dan, David’s presentations):interoperability, modeling, synthesis, integrity checking, prediction,
information dissemination, quick start to “poor man’s managed/curated data repositories”, foundation for “richer man’s repository, foundation for new communication mode, distributed collaboration, knowledge mgmt, knowledge from data, “democratizing information”, “build between”, …
• Input welcome: if you need something from the semantic web community you don’t see, tell us
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Some Pointers
• Ontologies Come of Age Paper: 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/
• DAML+OIL: http://www.daml.org/ , http://www.w3.org/TR/daml+oil-reference
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Extras
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What is an Ontology?
Catalog/ID
GeneralLogical
constraints
Terms/glossary
Thesauri“narrower
term”relation
Formalis-a
Frames(properties)
Informalis-a
Formalinstance
Value Restrs.
Disjointness, Inverse, part-
of…
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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 or other standards bodies
• 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
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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
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DAML+OIL -> W3C
• W3C Webont working group formed with DAML+OIL submission as starting point http://www.w3.org/Submission/2001/12/
• Web Ontology Working Group in the W3C Semantic Web Activity aimed at “extending the semantic reach of current XML and RDF meta-data efforts. “
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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
– Bristol: http://www.w3.org/2001/sw/WebOnt/ftf4– Expected recommendation status at w3c meeting in march.
• 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/
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Contact Information
www.ksl.stanford.edu/people/dlm
McGuinness NSF/NCAR October 30, 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, …)
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Simple Ontology-Enhanced Apps
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