Matching LCSH and User Vocabulary in the Library Catalog

Abstract

Central to subject searching is the match between user vocabulary and the headings from Library of Congress Subject-Headings (LCSH) used in a library catalog. This paper evaluates previous matching studies, proposes a detailed list of matching categories, and tests LCSH in a study using these categories. Exact and partial match categories are defined for single LCSH and multiple LCSH matches to user expressions. One no-match category is included. Transaction logs from ORION, UCLA's online Information system, were used to collect user expressions for a comparison of LCSH and user language. Results show that single LCSH headings match user expressions exactly about 47% of the time; that single subject heading matches, including exact matches, comprise 74% of the total; that partial matches, to both single and multiple headings, comprise about 21% of the total; and that no match occurs 5% of the time.