Visualizing OPAC subject headings.

Abstract

This paper aims at providing a robust, user-friendly and efficient navigation procedure in an online library catalog that is based on semantic information encapsulated within subject headings. Instead of relying on a static, predefined hierarchical navigation structure, the proposed navigation procedure relies on a dynamic, interactive graph-based structure. Subject headings and their relationships constitute the nodes and arcs respectively of the graph. Such a structure may be encoded in a variety of semantic-aware technologies implementing subject-based classification. The ultimate goal of the navigation procedure is to guide users in locating useful information as accurately and efficiently as possible. Design/methodology/approach – The building block of the proposed approach is the employment of ontologies. Specifically, users select subject headings by interacting with the prototype application which is based on an AJAX-powered web graphical user interface (GUI). The GUI communicates with an underlying ontology that comprises the subject headings and their interrelations. Such headings are used within the OPAC to semantically describe the contained assets. By selecting a specific subject heading, the proposed application addresses a typical search query to the OPAC containing the selected heading. A working functional application embedded within a real-world OPAC will be provided illustrating the effectiveness of the proposed approach. Findings – According to the proposed method, a GUI interface exposes the hierarchy of the subject headings employed within an OPAC, as well as all stated relations between such headings, as links that the user can follow, effectively traversing the ontology and formulating at the same time the actual query to the underlying OPAC. This act of interactive navigation through the library’s assets aids searchers in accurately formulating their queries, by offering broader or narrower concepts for selection or indicating alternative or related concepts they might be initially unaware of. The augmented exposition of inter-relations between concepts provides multiple paths for information retrieval and enables searchers to fulfill their information needs in a faster, more efficient and intuitive manner. Practical implications – The paper includes implications for the development of modern, semantic web applications focused on the library domain. The novel approach of visualizing subject headings could be further extended to visualize a number of other conceptualizations of the library domain. Originality/value – This paper fulfils an identified need to take advantage of the “hidden knowledge” existing within the library domain but, for a number of reasons, is never exposed to the library users.