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The Common Semantic ModelWhat, Why, How?

Patrick CassidyMITRE Corporation*

Presented at the

Fourth Semantic Interoperability for E-Government Conference

February 10, 2006 MITRE –McLean, Virginia

* NOTE: The author’s affiliation with The MITRE Corporation is provided for identification purposes only, and is not intended to convey or imply MITRE’s concurrence with, or support for, the positions, opinions or viewpoints expressed by the author.

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COSMO: What is It?

The Common Semantic Model (COSMO) is a basic set of ontology elements – classes, relations, functions, instances – similar to an upper ontology, intended to serve as the “conceptual defining vocabulary” that will permit specification of the meanings of any domain term or concept. It serves a function analogous to the “controlled defining vocabularies” used in some traditional dictionaries to define words.

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COSMO: Why is it needed?

• A Common set of defining concepts is necessary to permit domain concepts defined by different groups to be reusable for precise and consistent logical inference. The COSMO provides a common “vocabulary” with which to specify the meanings of concepts and terms.

• Without a common standard of meaning, it is not possible to reliably reuse knowledge specifications among different groups for automated inference.

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Who Needs a Common Semantic Model?

• Any computer system that needs to accurately communicate conceptual information needs a language in common with the receiving system

"Money is being spent on labs and hiring smart people who make products do unnatural acts together.”

Alan Shockley, manager of Enterprise Information Technology at EDS

Estimated costs of lack of data interoperability nationwide is over 100B/yr

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What Does it Mean to “Specify the meaning of a term”?

• “The biological mother of a person is a woman who has given birth to that person”

• {{?Mother isTheBiologicalMotherOf ?Child} impliesThat (ThereExists {((exactly one) ?Event) and ((exactly one) ?Date) and ((exactly one) ?Location)}

suchThat {{?Event isa BirthEvent} and {?Event occurredOn ?Date} and {?Event occurredAt ?Location} and {?Mother is (The Mother in ?Event)} and {?Child is (The Baby in ?Event)} and {(The BirthDate of ?Child) is ?Date} and {(The BirthPlace of ?Child) is ?Location}})}

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The Integrating Function of the Common Semantic Model

Obligation Duty

GenericObligation

SameAs

SameAs

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The Integrating Function of the Common Semantic Model –

via Domain-level Mapping

Obligation Duty

GenericObligation

SameAs

SameAs

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What A Common Semantic Model Isn’t

≠ A controlled vocabularyEach community can choose its own words to refer to concepts

≠ A mandated standardUsers can use any common ontology or none, as their own needs dictate

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Communities and Controlled Vocabularies

• Whenever a community of interest or community of practice is sufficiently homogeneous to agree on a controlled vocabulary, that vocabulary can serve as a linguistic signature of a particular context, which will be helpful in machine interpretation of text documents.

• i.e., multiple controlled vocabularies are good things. The Common Semantic Model can specify the relations between terms in community vocabularies.

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Concepts vs. WordsMathematical Theory / | \ / \ \ / | \ / \ | \ \ / | \ /

Axioms:(Every Cat has (( 4) Legs))

(Every House has ((atLeast 1) Door))

HouseCat

Siamese

Ontological Theory

Terminology

“Siamese Cat”

“Residential House”

“Haus”

“chat siamois”“Siamesische Katze”

“House”

“maison”

“Siamese feline”“Siamese”

“дом”

シャム猫

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Everybody Gets Everything They Want

• Nobody has to stop doing anything they want to

• Just learn the common defining language and use it - when you want to communicate

• It’s the job of the programmer to make it easy to learn and use

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Definition Acceptance Hierarchy

Executable Specification: Methods, Sequence, States

Axiomatic Ontology: Quasi-2nd Order, Function Terms

OpenCycSUMO DOLCE

Restricted FOL: OWL

Taxonomy/Thesaurus/Terminologyaccepts

accepts

is used in

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Methods? Isn’t Logic Enough?

• Q: Is there anything that cannot be stated in quasi-2nd order logic? If not, are methods necessary?

• A: Perhaps not, but methods with sequential instruction execution are a very efficient way to control inferential explosions. Avoiding long unnecessary inferential paths will probably be essential for practical problems.

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Contexts

• Q: Isn’t context important?

• A: Very. Existing ontologies have modules, contexts, or similar mechanisms (“microtheories”). More elaborate contextual reasoning may be necessary.

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How Can a COSMO be Developed?

• Within the ONTACWG:• http://colab.cim3.net/cgi-bin/wiki.pl?OntologyTaxonomyCoordinatingWG

– 130 participants

• Within the COSMO-WG:• http://colab.cim3.net/cgi-bin/wiki.pl?CosmoWG

– 50 Participants

• By construction and maintenance on the Wikis and the common web site:

• http://colab.cim3.net/file/work/SICoP/ontac/reference/

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Any Other Possibilities?

• Collaboration among Upper Ontology Custodians?

– e.g. via an Upper Ontology Summit –To be held on March 15th

At NIST, Bethesda Maryland

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What is Available So Far?

• A Bare Taxonomy, a merger of parts of the top levels of OpenCyc, SUMO, DOLCE, BFO, and ISO15926– Simple Indented list:– http://colab.cim3.net/cgi-bin/wiki.pl?CosmoWG/TopLevel2

– OWL version:http://colab.cim3.net/file/work/SICoP/ontac/reference/ProtegeOntologies/TopLevel07.owl

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The Good News and the Bad News

• First The Bad News– There are no Applications to

Demonstrate the Utility of the nascent COSMO

• Now the good News:– There are no Legacy Applications that

Will Break if we Make Drastic changes

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What Formats Will be Supported?

• Some variant of Common Logic– SKIF or IKL (?)

• quasi-second order with function terms

• OWLOWL-full(?)

• OWL + SWRL (when available)

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How Will the COSMO be Tested?

• OWL version – via a DL reasoner– e.g. Protege-OWL + Pellet

• FOL version – via a FOL prover– e.g. SigmaKEE using Vampire

Incrementally, as ontology components are added

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isaPhysicalPartOf -- inferences

(=>

(isaPhysicalPartOf ?P ?W)

(and

(isaPartOf ?P ?W)

(isLocatedAt ?P ?W)))

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isaPhysicalPartOf -- definition <owl:ObjectProperty rdf:ID="isaPhysicalPartOf"> <rdfs:domain> <_SYN-CLASS rdf:ID="PartiallyTangible_Cyc__Object_SUMO__physical-

endurant_DOLCE_"/> </rdfs:domain> <rdfs:range rdf:resource="#PartiallyTangible_Cyc__Object_SUMO__physical-

endurant_DOLCE_"/> <rdfs:subPropertyOf> <owl:ObjectProperty rdf:ID="isLocatedAt"/> </rdfs:subPropertyOf> <rdfs:subPropertyOf> <owl:ObjectProperty rdf:ID="isaPartOf"/> </rdfs:subPropertyOf> <rdfs:comment rdf:datatype="http://www.w3.org/2001/XMLSchema#string" >isaPhysicalPartOf relates physical objects to the larger objects of which they may be

parts. This is time-dependent and applies only to instances at a particular time. It is transitive.</rdfs:comment>

<rdf:type rdf:resource="http://www.w3.org/2002/07/owl#TransitiveProperty"/> </owl:ObjectProperty>

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What Else is Needed?

• A Good English-Language Interface– e.g. some Controlled English variant

“Colonel Mustard killed Miss Scarlet in the Kitchen with a Knife”

=>

{{“Colonel Mustard” killed “Miss Scarlet”}, (in the Kitchen) (using-i a Knife)}

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What Else is Needed?

More Input

• How do you specify meanings in your system?– Let us know

• What do you need to be able to create precise specifications of meaning?

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Who is Paying for All This?

• At present, No One (SICoP support for Web Site)

• Funding will be needed for a fully-functional COSMO with utilities and Demo Applications

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QUESTIONS?

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Tco ≈ 6 + 240/(1 + 4*M)