OWL Web Ontology Language Summary IHan HSIAO (Sharon)

OWL-introduction Definition: a language represents knowledge about a particular domain; a specification of conceptualization. Authors: Web Ontology Working Group as part of the W3C Semantic Web Activity Publish date: 2004/02/10 Purpose: being used to publish and share sets of terms, supporting advanced Web search, software agents and knowledge management Sublanguage: OWL Lite, OWL DL, OWL Full

OWL set of documents The OWL Overview gives a simple introduction to OWL by providing a language feature listing with very brief feature descriptions; The OWL Guide demonstrates the use of the OWL by providing an extended example. It also provides a glossary of the terminology used in these documents; The OWL Reference gives a systematic and compact (but still informally stated) description of all the modeling primitives of OWL; The OWL Semantics and Abstract Syntax document is the final and formally stated normative definition of the language; The OWL Web Ontology Language Test Cases document contains a large set of test cases for the language; The OWL Use Cases and Requirements document contains a set of use cases for a web ontology language and compiles a set of requirements for OWL.

Characteristics Ontology structure Elements: classes, properties, instances of classes, and relationships between these instances Ontology mapping Ontology version OWL DL (Description Logic): support existing Description Logic business segment and to provide computational properties OWL Full: complete OWL language. It allows free mixing of OWL with RDF Schema and, like RDF Schema, does not enforce a strict separation of classes, properties, individuals and data values. OWL Lite: It is a sublanguage of OWL DL that supports only a subset of the OWL language constructs. abides by the same semantic restrictions as OWL

Evolution/Changes OWL: –a vocabulary extension of RDF (the Resource Description Framework) –a revision of the DAML+OIL web ontology languageDAML+OIL web ontology language Major changes: –Namespace, RDF Schema, restrictions etc.

Concerns/Objections & Current Status Concerns: –OWL not allow explicit declarations –OWL Abstract Syntax and OWL RDF syntax rely on the separation between object and data property names for disambiguation, makes implementing OWL parsers difficult –OWL Abstract Syntax cannot be translated into OWL RDF syntax without loss of information –Are we applying good ontologies or not? Cureent Status: 2004/05/28: project goal achieved. RDF and OWL are Semantic Web standards that provide a framework for asset management, enterprise integration and the sharing and reuse of data on the Web.