document.113

Ontologies are a popular research topic in various communities such as knowledge
engineering, natural language processing, cooperative information systems, intelligent
information integration, and knowledge management. They provide a shared and common
understanding of a domain that can be communicated between people and
heterogeneous and widely spread application systems. They have been developed in
Artificial Intelligence to facilitate 
knowledge sharing and reuse
. There, problem-solving methods
(cf. [Fensel, 2000]) describe the reasoning behaviour and 
ontologies
describe
the static domain knowledge of a knowledge-based system. Some Examples are KIF
[Genesereth, 1991], Ontolingua [Gruber, 1993], CYC [Lenat & Guha, 1990], and
KQML [KQML]. Recent articles covering various aspects of ontologies can be found in
[Uschold & Grüninger, 1996], [van Heijst et al., 1997], [Studer et al., 1998], [Benjamins
et al., 1999], [Gomez Perez & Benjamins, 1999]. An ontology provides an explicit
conceptualisation (i.e., 
meta-information
) that describe the semantics of the data. They
have a similar function as a database schema. The differences are
1
:
•
A language for defining ontologies is syntactically and semantically richer than
common approaches for databases.
•
The information that is described by an ontology consists of semi-structured
natural language texts and not tabular information.
•
An ontology must be a shared and consensual terminology because it is used for
information sharing and exchange.
•
An ontology provides a domain theory and not the structure of a data container