1. OWL Language off Textbook Ch. 10
Atilla Elçi
06 Dec. 2006
CmpE 583 Fall 2006

2. OWL? Language to support the Semantic Web
Logical layer in SemWeb arch.
Based on RDFS and extends it
Has additional language features to for describing ontologies
W3C’s recommended ontology language for representing information in the SemWeb.
06 Dec. 2006
CmpE 583 Fall 2006

3. OWL History DARPA Agent Markup Language (DAML):
DARPA research program:
2000
Obj.: interoperability among DoD IT systems.
Dr. James Handler (U. of Maryland) initiated.
Murray Burke & later Dr. Mark Greaves
MIT took part.
European Project: Ontology Interface Layer (OIL)
Joint EU/US committee on OIL merged the two in 2001: DAML+OIL
DAML+OIL:
To define ontologies for communicating agents
A thin layer on top of RDFS
Starting of W3C Web Ontology Working Group of W3C Semantic Web Activity:
Dr. James Handler & Dr. Guus Schreiber
Obj.: Describing expressive semantics: A formal semantics to precisely define the meaning of expressions and valid inferences from them.
Outcome is OWL.
OWL: adopted as W3C recommendaiton on February 14, 2004.
06 Dec. 2006
CmpE 583 Fall 2006

4. OWL Definition: Recommendations
OWL authoriative description: all dated Feb.24, 2004.
OWL Overview: Provides an OWL introduction
OWL Guide: Demonstrates the use of OWL with examples
OWL Reference: Structured informal introduction to OWL constructs
OWL Semantics and Abstract Syntax: Provides the normative (that is, official) definiton of OWL
OWL Test Cases: Provides test cases for OWL
OWL Use Cases and Requirements: Specifies usage scenarios, goals and requirements
06 Dec. 2006
CmpE 583 Fall 2006

5. OWL Definition: namespace
Recommended namespace prefix:
owl
Namespace URI:
MIME type:
Application/rdf+xml
06 Dec. 2006
CmpE 583 Fall 2006

6. OWL Flavors (dialects, species, variants)
OWL comes in three flavors in order to support different groups of users needing varying levels of expressional capability :
OWL Lite:
A simple sublanguage of OWL Full: minimal set of features
Has a subset of OWL Full features; even some are restricted
For transition from DB, XML, or RDF(S) information representation to ontology use
Supports efficient reasoning
Requires much simpler tools than DL / Full.
OWL DL:
A Description Language variant of OWL Full
Uses OWL Full constructs but restricts usage of some of them
Restrictions render OWL DL as decidable: => computaitons will finish in a finite amount of time
Obj.: to support reasoning applications.
OWL Full:
The complete OWL Language
Superset of RDF
No restrictions on RDF doc.
06 Dec. 2006
CmpE 583 Fall 2006