Ontology-based Knowledge Organization Systems in Digital Libraries:
A Comparison of Experiments in OWL and KAON Ontologies
Shalini R. Urs
International School of Information Management
University of Mysore
Angrosh M A
University of Mysore
Keywords: Ontology; Knowledge Representation Formalisms; Description Logics; Web Ontology
Language (OWL); Karlsruhe Ontology (KAON); Digital Libraries; Semantic Web; Facet Analysis;
Ontology Markup Languages; Resource Description Language Schema (RDFS).
Grounded on a strong belief that ontologies enhance the performance of information retrieval systems, there
has been an upsurge of interest in ontologies. Its importance is identified in diverse research fields such as
knowledge engineering, knowledge representation, qualitative modeling, language engineering, database
design, information integration, object-oriented analysis, information retrieval and extraction, knowledge
management and agent-based systems design (Guarino, 1998). While the role-played by ontologies,
automatically lends a place of legitimacy for these tools, research in this area gains greater significance in
the wake of various challenges faced in the contemporary digital environment. With the objective of
overcoming various pitfalls associated with current search mechanisms, ontologies are increasingly used for
developing efficient information retrieval systems. An indicator of research interest in the area of ontology
is the Swoogle, a search engine for Semantic Web documents, terms and data found on the Web (Ding, Li
et al, 2004). Given the complex nature of the digital content archived in digital libraries, ontologies can be
employed for designing efficient forms of information retrieval in digital libraries.
Knowledge representation assumes greater significance due to its crucial role in ontology development.
These systems aid in developing intelligent information systems, wherein the notion of intelligence implies
the ability of the system to find implicit consequences of its explicitly represented knowledge (Baader and
Nutt, 2003). Knowledge representation formalisms such as ‘Description Logics’ are used to obtain explicit
knowledge representation of the subject domain. These representations are developed into ontologies,
which are used for developing intelligent information systems. Against this backdrop, the paper examines
the use of Description Logics for conceptually modeling a chosen domain, which would be utilized for
developing domain ontologies. The knowledge representation languages identified for this purpose are Web
Ontology Language (OWL) and KArlsruhe ONtology (KAON) language. Drawing upon the various
technical constructs in developing ontology-based information systems, the paper explains the working of
the prototypes and also presents a comparative study of the two prototypes.