Representing Knowledge in OWL

A. W. Crapo, last revised 07/07/2004

Copyright General Electric Company 2004, 2005, 2006

This document is meant to provide discussion and examples of how to create useful ontological constructs using the Web Ontology Language OWL. Unless otherwise noted, all language elements will be at most OWL DL in order to have confidence in the computability of OWL-based models built following this methodology. While OWL has an abstract syntax, this document assumes the OWL syntax built on RDF, albeit the abbreviated form . (See the RDF Primer for more information on RDF syntax.)

Index

An Introduction to Description Logics (DL) Terminology

OWL Basics

• Classes
• Individuals (Instances)
• Properties
  • Object Properties
  • Datatype Properties
• Sowa's Roles

Advanced OWL 

• Importing Other Ontologies into an OWL File
• Partonomies (part-of relationships)
• Sequences and Ordered Sets (OWL Full) 

OWL Editing Environments

OWL Reasoning and Reasoners

• Introductory Example
• Temporal Reasoning
• Reasoners
  • Jena
  • JTP (Java Theorem Prover)
  • Racer (Renamed ABox and Concept Expression Reasoner)

Notes

• Use of DOCTYPE for readability
• XML Namespaces
• rdf:resource versus rdf:about

Unanswered Questions/Problems

Other Resources

• RDF Primer
• Protege-OWL Tutorials: 
  • A Practical Guide to Building OWL Ontologies with the Protege-OWL Plugin by Matthew Horridge
  • Editing OWL Ontologies with Protégé by Holger Knubauch, Stanford University
• OWL Ontology Library
• OWL Validator Website
• Jena 2: A Java framework for writing Semantic Web applications
• To search the Web for OWL ontologies (files): http://www.google.com/search?q=filetype:owl+owl&hl=en&lr=&ie=UTF-8&start=40&sa=N
• Instance Store for combined database and reasoner handling of large numbers of assertions
• Draft Treatise on Using Classes as Values (Natasha Noy, Stanford; see also discussion thread)

Copyright 2004 General Electric
A. W. Crapo, GE Global Research
Last revised 07/07/2004