The use of Library of Congress Subject Headings in digital collections

Purpose - This paper attempts to explain the wide dissemination of Library of Congress Subject Headings (LCSH) within digital libraries and presents some of the advantages and disadvantages of using this controlled vocabulary in digital collections. The paper also presents other classifications used in digital collections for subject access and explores ways of improving search functionality in digital collections that employ LCSH. Design/methodology/approach - Unlike traditional libraries that use Library of Congress Classification for organization and retrieval, digital libraries use metadata forms for organization and retrieval. The collections exist in cyberspace of the internet which is known for containing the universe of knowledge. The use of LCSH for information retrieval has been widely criticized for its difficulty of use and its information retrieval effectiveness in online environments. The Library of Congress (LOC) has claimed the headings were not based on comprehensive principles nor ever intended to cover the universe of knowledge. Despite these claims and criticisms, LCSH is the most popular choice for subject access in digital libraries. Findings - The number of digital collections increases every year and LCSH is still the most popular choice of controlled vocabulary for subject access. Of the numerous criticisms, difficulties of use and user unfamiliarity are the greatest disadvantages of using LCSH for subject access. Average users only have a vague notion of what they are looking for when initializing a search. More work is required in automated generation of subject headings and increased usage of LCSH in faceted search retrieval systems. This will provide users with better access to the LCSH used in the back end of information retrieval. Originality/value - The Greek researchers who developed the Dissertation DSPace system believe this type of module will eventually replace the traditional keyword-based indexing back ends employed by many information retrieval modules within current digital library systems. The system offers the type of access and interactivity that will acquaint users with how LCSH looks and is used. Faceted search and automated pattern matching using an ontology based on LCSH have the best promise of overcoming the disadvantages that have always plagued the LOC-controlled vocabulary. These retrieval techniques give LCSH an opportunity to finally achieve the optimal precision and recall it has so far failed to deliver.