Ontology Engineering

Lab #5 – September 30, 2013

Review for Quiz Versioning Ontologies

prohibited combinations of Ontology IRIs and Version IRIs

uniqueness constraints RDF

Triple format Graph representation Syntax rules – e.g. subject cannot be a literal

Review for Quiz RDF, RDFS and OWL

Translation into natural language Example:

OE_002 rdf:type owl:Class translates to: OE_002 is a Class

Example: OE_002 rdf:type owl:Class OE_101 rdf:type OE_002 OE_102 rdf:type OE_002 OE_004 rdf:type owl:Property OE_101 OE_004 OE_102 Translates to: OE_101 and OE_102 are instances of class

OE_002 and OE_101 is related to OE_102 by the property OE_004

Review for Quiz RDF, RDFS and OWL

Translation from natural language Example:

Apples are a kind of Fruit Translates to:

Apple rdf:type owl:Class Fruit rdf:type owl:Class Apple rdfs:SubClassOf Fruit

Example: This apple is green Translates to:

Apple rdf:type owl:Class OE_001 rdf:type Apple Green rdf:type owl:Class OE_002 rdf:type Green has_quality rdf:type owl:Property OE_001 has_quality OE_002

Review for Quiz Identify and explain problems in taxonomies

Use – Mention error Is_a overloading (e.g. use of part of relation

instead of subclass relation to order the taxonomy Logic of Terms Non-Disjoint Classes

Terminology Primitive vs. Defined Classes Enumerative Class

Review for Quiz Class Restrictions – identify kind of restriction

Subclass restrictions as necessary conditions Equivalent to restrictions as necessary and

sufficient conditions Existential restrictions Universal restrictions Cardinality restrictions

Min, Max, Exactly Example:

Every International traveller has at least one passport Subclass restriction & Min Cardinality restriction

Review for Quiz Open and Closed World Assumptions

Explain inference based upon either Example: Under a Closed World Assumption which of the

following statements is implied by the statement that 2 is an even number and that no other information about 2 is available? 2 is not an odd number 2 is not a prime number 2 is divisible by 2 2 is greater than 1

Closure Axioms Create a closure axiom for the class RDF statement that

has three subclass restrictions: Every RDF Statement has part some Subject Every RDF Statement has part some Predicate Every RDF Statement has part some Object Solution: Every RDF has part only (Subject or Predicate or Object)

Review for Quiz Coverage Axiom

Example: Create a coverage axiom for the class Widget that has three subclasses: SmallWidget, MediumWidget, and LargeWidget The class Widget is a subclass of the union of Small, Medium

and Large Widget Classes

Inferences based upon the types of Object Properties Functional, Reflexive, Irreflexive, Symmetric,

Asymmetric and Transitive Example: The property R is an asymmetric and

transitive property. What can be inferred from the facts: x is related by R to y y is related by R to z

Review for Quiz Review Session – Saturday 5th 10am – 12pm.

Meet by Philosophy Department Office in 1st floor of Park Hall

BFO version 1.1 can be downloaded from http://www.ifomis.org/bfo. In the Implementations section click on the OWL-DL hyperlink