A presentation in lab seminar of Intelligent Web Business Lab : http://smartlab.yonsei.ac.kr/

1. OWL 2.0 Primer
Classes, Properties, and Individuals

2.  Contents
• Basic Notions
• Classes, Properties, Individuals & basic
modeling with them
OWL 2.0
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3.  Basic Notions
• OWL2 is a knowledge representation language.
Axioms: the basic statements that an OWL ontology expresses.
Entities: elements used to refer to real-world objects.
Expressions: combinations of entities to form complex descriptions
from basic ones
OWL 2.0
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4. 1. Mary and John are married.
2. Mary is female.
Axioms
individuals
properties
married
classes
Entities
Mary, John
female
Female professor
Expressions
Entity
+
Entity
female
OWL 2.0
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professor
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5.  Classes and Instances(Individuals)
An individual named Mary and states this
individual is a person
Functional-Style Syntax
RDF-XML Syntax
<owl:Class rdf:ID=“Person”/>
ClassAssertion( :Person :Mary)
1.<owl:Thing rdf:ID=“Mary”/>
<owl:Thing rdf:about=“Mary”>
<rdf:type rdf:resource=“#Person”>
</owl:Thing>
2.<Person rdf:ID=“Mary”/>
OWL 2.0
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6.  Class Hierarchies
Every individual which is specified as an instance
of the class Woman is also an instance of the
class Person as well.
Functional-Style Syntax
RDF-XML Syntax
<owl:Class rdf:ID=“Woman”/>
SubClassOf( :Mother :Woman)
<owl:Class rdf:ID=“Mother”>
<rdfs:subClassOf rdf:resource=“#Woman”/>
</owl:Class>
OWL 2.0
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7.  Class Hierarchies
Every instance of the class Person is also an
instance of class Human, and vice versa.
Functional-Style Syntax
RDF-XML Syntax
<owl:Class rdf:ID=“Human”/>
EquivalentClasses( :Person :Human )
<owl:Class rdf:ID=“Person”>
<owl:equivalentClass rdf:resource=“#Human”/>
</owl:Class>
OWL 2.0
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8.  Class Disjointness
Incompatibility relationship between class of
Woman and Man.
Functional-Style Syntax
RDF-XML Syntax
<owl:Class rdf:ID=“Man”/>
DisjointClasses( :Woman :Man)
<owl:Class rdf:ID=“Woman”>
<owl:disjointWith rdf:resource=“#Man”/>
</owl:Class>
OWL 2.0
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9.  Object Properties
John
hasWife
Mary
Mary is John’s wife
Functional-Style Syntax
RDF-XML Syntax
<Person rdf:ID=“Mary”/>
ObjectPropertyAssertion( :hasWife :John :Mary)
<Person rdf:ID=“John”>
<hasWife rdf:resource=“#Mary”/>
</Person>
OWL 2.0
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10.  Property Hierarchies
Whenever B is known to be A’s wife, it is also
known to be A’s spouse.
Functional-Style Syntax
SubObjectPropertyOf( :hasWife :hasSpouse )
RDF-XML Syntax
<owl:ObjectProperty rdf:ID=“hasWife”>
<rdfs:subPropertyOf rdf:resource=“#hasSpouse”/>
…
…
</owl:ObjectProperty>
OWL 2.0
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11.  Domain and Range Restrictions
B is the wife of A obviously implies that B is a
woman and A is a man.
Functional-Style Syntax
RDF-XML Syntax
<owl:Class rdf:ID=“Man”/>
<owl:Class rdf:ID=“Woman”/>
ObjectPropertyDomain( :hasWife :Man )
ObjectPropertyRange( :hasWife :Woman )
<owl:ObjectProperty rdf:ID=“hasWife”>
<rdfs:domain rdf:resource=“#Man”/>
<rdfs:range rdf:resource=“#Woman”/>
</owl:ObjectProperty>
OWL 2.0
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12.  Equality and Inequality of Individuals
John and Bill are not the same individuals.
James and Jim are the same individuals.
Functional-Style Syntax
RDF-XML Syntax
1.DifferentIndividuals( :John :Bill )
<Man rdf:ID=“John”>
<owl:differentFrom rdf:resource=“#Bill”/>
</Man>
2.SameIndividual( :James :Jim )
<Man rdf:ID=“James”>
<owl:sameAs rdf:resource=“#Jim”/>
</Man>
OWL 2.0
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13.  Datatypes
John’s age is 51
Functional-Style Syntax
RDF-XML Syntax
<Man rdf:ID=“John”>
<hasAge rdf:datatype=“&xsd;integer”>51</hasAge>
</Man>
DataPropertyAssertion( :hasAge :John “51”^^xsd:integer )
OWL 2.0
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14.  Domain and range of Datatypes
Domain and range of datatypeproperty
Functional-Style Syntax
RDF-XML Syntax
DataPropertyDomain( :hasAge :Person )
DataPropertyRange( :hasAge xsd:nonNegativeInteger )
OWL 2.0
<owl:DatatypeProperty rdf:ID=“hasAge”>
<rdfs:domain rdf:resource=“Person”/>
<rdfs:range
rdf:resource=“&xsd;nonNegativeInteger”/>
</owl:DatatypeProperty>
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15. Protégé 3.4.4
Protégé 4.1 beta
OWL 2.0
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16. Q&A
OWL 2.0
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