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Semantic Semantic Reasoning and Reasoning and
the Buffy the Buffy ParadigmParadigm
Bill McDaniel, edpBill McDaniel, edp
Adobe®
Sr. Scientist04/26/2005
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The Buffy ParadigmThe Buffy Paradigm First introduced in: First introduced in:
Biological Warfare and the Buffy ParadigmBiological Warfare and the Buffy ParadigmAnthony H. Cordesman, Sept. 29, 2001Anthony H. Cordesman, Sept. 29, 2001
Arleigh A. Burke Chair in StrategyArleigh A. Burke Chair in StrategyCenter for Strategic and International StudiesCenter for Strategic and International Studies
Describes Common Domain AspectsDescribes Common Domain Aspects Uncertain situationsUncertain situations Incomplete knowledgeIncomplete knowledge
Counterbalanced by the Buffy SyndromeCounterbalanced by the Buffy Syndrome An unrealistic search for certaintyAn unrealistic search for certainty
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Characteristics of the BPCharacteristics of the BP
High degree of uncertaintyHigh degree of uncertainty Complexity and chaos are the normComplexity and chaos are the norm
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Characteristics of the BPCharacteristics of the BP Bad or uncertain expertiseBad or uncertain expertise
Inconsistent, erroneous knowledgeInconsistent, erroneous knowledge Contradictory rulesContradictory rules
Priorities change rapidlyPriorities change rapidly Tactical issues overrun strategic thinkingTactical issues overrun strategic thinking
Past performance is not a valid predictorPast performance is not a valid predictor Each problem must be solved independentlyEach problem must be solved independently
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Characteristics of the BPCharacteristics of the BP
Arcane knowledge is insufficientArcane knowledge is insufficient Fails to predict the true solutionFails to predict the true solution
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Characteristics of the BPCharacteristics of the BP Certainty is a marker for incorrectnessCertainty is a marker for incorrectness
More certainty implies less accuracyMore certainty implies less accuracy
Strategy collapses in the face of realitiesStrategy collapses in the face of realities Tactical considerations overrun planningTactical considerations overrun planning
No success eliminates future problemsNo success eliminates future problems The next issue is a transaction awayThe next issue is a transaction away
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Semantic Web TechnologiesSemantic Web Technologies
RDFRDF Describes relationships between entitiesDescribes relationships between entities Provides a reasoning frameworkProvides a reasoning framework Encapsulates knowledgeEncapsulates knowledge
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Semantic Web TechnologiesSemantic Web Technologies
RDFRDF Suffers from the certainty problemSuffers from the certainty problem Does not lend itself to reasonersDoes not lend itself to reasoners Not XML-ish enough for someNot XML-ish enough for some
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Semantic OntologiesSemantic Ontologies
OWLOWL The Web Ontology Language The Web Ontology Language
Provides XML framework for reasonersProvides XML framework for reasoners
Addresses the issues of RDFAddresses the issues of RDF
Forms a bridge from RDF to XMLForms a bridge from RDF to XML
Allows disambiguation of vocabulariesAllows disambiguation of vocabularies
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Semantic issues with XMLSemantic issues with XML Schemas are NOT OntologiesSchemas are NOT Ontologies
Ontologies provide namesOntologies provide names Schemas and vocabularies do as wellSchemas and vocabularies do as well
But…But…
Ontologies Represent KnowledgeOntologies Represent Knowledge RDF + OWL = KRRDF + OWL = KR Ontologies allow uncertaintyOntologies allow uncertainty
Can deal with ambiguityCan deal with ambiguity Can drive reasoners with relationshipsCan drive reasoners with relationships Can be contained within other ontologiesCan be contained within other ontologies
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Vocabulary ResolutionVocabulary Resolution Consider two xml schemas Consider two xml schemas One uses the name ‘zip’One uses the name ‘zip’ One uses the name ‘zipcode’One uses the name ‘zipcode’
zip
zipcode
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Vocabulary ResolutionVocabulary Resolution Ontological viewOntological view
Provides an is_a relationshipProvides an is_a relationship Defines a virtual inference linkDefines a virtual inference link
zip
zipcode
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Ontological PowerOntological Power Ontologies express rulesOntologies express rules
Designate inference rulesDesignate inference rules Make inferencing chains possibleMake inferencing chains possible
Allow incomplete knowledgeAllow incomplete knowledge ‘‘Person’ in ‘Ithaca’ impliesPerson’ in ‘Ithaca’ implies ‘‘Person’ in ‘New York’Person’ in ‘New York’
Can resolve ambiguitiesCan resolve ambiguities A ‘unit’ may be part_of an ‘item’A ‘unit’ may be part_of an ‘item’ An ‘item’ may be part_of ‘units’An ‘item’ may be part_of ‘units’
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Semantics and VocabulariesSemantics and Vocabularies
Ontologies can manage vocabulariesOntologies can manage vocabularies
Allow for greater flexibilityAllow for greater flexibility Lessen need for consistencyLessen need for consistency Allow XML vocabularies to emerge from Allow XML vocabularies to emerge from
database schemasdatabase schemas
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Semantics and the BPSemantics and the BP
Semantics Semantics Adapt to changing prioritiesAdapt to changing priorities Represent uncertain knowledgeRepresent uncertain knowledge Allow reasoning with contradictory informationAllow reasoning with contradictory information Improve predicatabilityImprove predicatability
Semantics + XML Vocabularies provide Semantics + XML Vocabularies provide an answer to the Buffy Paradigman answer to the Buffy Paradigm