OWL verses UML Jan Pettersen Nytun, UiA 1 S O P [1]: The - - PowerPoint PPT Presentation

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Knowledge Representation Part VIIc

OWL verses UML

Jan Pettersen Nytun, UiA

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[1]: “The languages were devised to fulfill different purposes. While OWL supports the representation of knowledge about a system, UML was developed primarily to support the construction of a (software) system.”

Jan Pettersen Nytun, UiA, page 2

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Open-World versus Closed-World Interpretation Assumptions

[1]: “The UML is oriented towards data modeling and system construction … knowledge is implicitly viewed as being complete. OWL, in contrast, interprets models as potentially representing partial knowledge.”

Jan Pettersen Nytun, UiA, page 3

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[1] Unique Name Assumption & Synonyms

• OWL allows the definition of synonyms for

classes, properties and individual descriptions.

• UML assumes that every name has a unique

interpretation, i.e., the unique name assumption.

Jan Pettersen Nytun, UiA, page 4

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[1] Sufficient Conditions & Defined vs. Primitive Concepts

• One of the purposes of OWL ontologies is

to facilitate automatic classification.

• The UML does not provide native

assistance in the definition of sufficient conditions or defined classes.

Jan Pettersen Nytun, UiA, page 5

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UML  OWL

Jan Pettersen Nytun, UiA, page 6

Person name : String Institution name : String

employee employedAt

* 1

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Jan Pettersen Nytun, UiA, page 7

Person name : String In UML a class is a namespace by itself. Institution name : String I.e., property name in class Person and property name in class Institution are different entities. Properties in OWL are globally scoped. Why is the following not a good idea?

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Simulate the namespace of the class by using class name as prefix.

Jan Pettersen Nytun, UiA, page 8

Person hasPersonName : String

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Multiplicity of hasPersonName is by default one.

Jan Pettersen Nytun, UiA, page 9

Person hasPersonName : String

:Person rdf:type owl:Class ; rdfs:subClassOf [ rdf:type owl:Restriction ;

• wl:onProperty :hasPersonName ;
• wl:qualifiedCardinality

"1"^^xsd:nonNegativeInteger ;

• wl:onDataRange xsd:string

] .

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Starting the reasoner – what is inferred?

Jan Pettersen Nytun, UiA, page 10

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Jan Pettersen Nytun, UiA, page 11

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Jan Pettersen Nytun, UiA, page 12

Remove Person as Domain and run reasoner – what is inferred?

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Jan Pettersen Nytun, UiA, page 13

Nothing is inferred!

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Jan Pettersen Nytun, UiA, page 14

Make Person a defined class. Run reasoner – what is inferred?

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We have an individual with one hasPersonName property specified. But still this individual is not classified as a Person - why?

Jan Pettersen Nytun, UiA, page 15

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• OWL makes the open world assumption.
• In our example this means: There may be

more hasPersonName properties for our individual.

Jan Pettersen Nytun, UiA, page 16

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• It is possible to specify that the individual has
• nly "Jan Pettersen"^^xsd:string

as value for property hasPersonName.

Jan Pettersen Nytun, UiA, page 17

Inferred by reasoner

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Better solution:

Jan Pettersen Nytun, UiA, Ontologies, page 18

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UML  OWL

Jan Pettersen Nytun, UiA, page 19

Person name : String Institution name : String

employee employedAt

* 1

Person name : String Institution name : String

institutionHas- EmployedPerson personIsEmployed- AtInstitution

* 1

“unique naming”

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Jan Pettersen Nytun, UiA, page 20

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Jan Pettersen Nytun, UiA, Ontologies, page 21

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References

Jan Pettersen Nytun, UiA, Propositional Calculus, page 22

[1] A Detailed Comparison of UML and OWL, Kilian Kiko & Colin Atkinson, https://ub-madoc.bib.uni-mannheim.de/1898/1/TR2008_004.pdf