Use of Subject Metadata in Library Discovery Systems: A Global Survey

This paper reports on a survey of research library catalogs and the ways these information retrieval systems support subject searching, the use of knowledge organization systems (KOSs), and the subject-searching options made available to users. The research was conducted by the International Society for Knowledge Organization (ISKO) Scientific and Technical Advisory Council (STAC) Working Group on Subject Access Metadata. Libraries commonly use KOSs such as general subject heading and classification systems, subject-specific thesauri, and other controlled vocabularies. However, there is concern that many library discovery systems do not provide easy or seamless access to this enriched metadata. The study examined available subject-searching and browsing features and explored barriers to their use. A survey of 114 academic and research libraries in 34 countries revealed widespread adoption of discovery systems, although many institutions continue to rely on Online Public Access Catalogs (OPACs) as the primary interface for subject searching. Libraries reported using a range of library management and discovery systems from suppliers including Ex Libris, SirsiDynix, EBSCO, Koha, and OCLC. Frequently used general KOSs include Library of Congress Subject Headings, Dewey Decimal Classification, Universal Decimal Classification, and the Chinese Library Classification, while Medical Subject Headings was the most commonly cited domain-specific system. Reported barriers include limited user familiarity with KOSs, system complexity, lack of natural-language access, language issues, and interface design problems. The ultimate goal of the research is to develop guidelines for improving access to enriched subject metadata in library discovery systems.