In this article, an effort is made to take advantage of the inherent semantic expressiveness existing within LCSHs, in order to provide more efficient subject-based information retrieval in digital libraries.
The first step towards this goal is to extend the syndetic structure (i.e., BT/NT/RT) running through LCSHs, with subdivision-based relations. As will be demonstrated later in this article, the provision of greater connectivity between LCSHs results in the emergence of more effective, subject-based information retrieval modules within digital libraries.
After extending the syndetic structure, the derived extended structure is mapped to an accordingly designed ontology schema. Such schema can be applied to any digital library containing subject descriptors according to the LCSH guidelines.
Finally, in order to exploit the semantic richness of the underlying ontology, an adequate user interface is presented. The interface enables users to familiarize themselves with the terminology employed within LCSHs and guides them to select the subject that best matches their information needs. The guided navigation is based on the relations between subject headings that were derived from the aforementioned extended syndetic structure.