Obtaining the Dewey Decimal Classification Number from other databases: a catalog clean-up project

The increasing availability of online catalogs and bibliographical databases allows not only for copy cataloging, but also for the retrieval of atomic information useful within the catalog. To this end, Dewey decimal numbers were imported from national and international sources by means of the unique identifier ISBN. Technical specifications have been developed to locate the records to be retrieved, to query external databases, to extract the Dewey decimal classification numbers and add them to the catalog. The exceptionally large amount of Dewey numbers added to the catalog has improved the semantic usability of the OPAC. The procedure established has also facilitated the collection of information on the use of the Dewey Decimal System in the various databases used and allowed to make certain comparisons between them. The tools employed can be used analogously for data-retrieval operations in the catalog, as an aid in the cataloging process, or to improve the OPAC in either a static or dynamic manner. Taking into account its virtually exclusive practical purpose, this work is characterized by practical rather than theoretical choices. However, the experience acquired opens up areas even in the field of academic research.