The management of large amounts of information and knowledge is of ever increasing importance in today's large organisations. With the ongoing ease of supplying information online, especially in corporate intranets and knowledge bases, finding the right information becomes an increasingly difficult task. Ontologies have been proposed to be a solution to this problem and have been successfully applied to improve knowledge management [1] and search in specialized domains [9].
However, the task of constructing an ontology still requires much effort and is often carried out in an ad-hoc manner. Only few methodologies exist [2, 10] to improve the latter situation and are often extremely complex requiring extensive training and expertise.
We present a novel approach to acquire an initial application ontology for the management of document collections. Our approach builds on the reuse of existing thesauri. Many companies have elaborated taxonomies of products, services and corporate thesauri to ensure proper use of terminology in internal and external documents. Such resources form an important intellectual asset of the business and maybe reused to form an initial ontology.
However, the utility of the ontology in document management is judged by the quality of document retrieval. This quality is largely influenced by the consonance of ontological terms with keywords occurring in managed documents. Unfortunately, this consonance is not met in large-scale thesauri. Hence, we developed an ontology pruning approach, which removes unneeded terms from the thesaurus via a heuristic analysis of terms contained in a document collection. Thereby we ensure that the ontology is focused to the intended document collection.
The usefulness of ontology pruning is emphasized by the results that could be obtained in the AOS project carried out by UN FAO, where we were challenged to acquire an initial ontology for document management in the biosecurity domain.
The paper is structured as follows. Section 2 details the pruning approach. We then elaborate possibilities for evaluation of the pruning approach in section 3. Section 4 presents the results of the evaluation carried out in the context of the UN FAO AOS project [6]. We conclude summarizing our contribution and discussing possible future directions.
