Indextermen

Indextermen are words or phrases assigned to a document to represent its topics and themes, with the aim of supporting discovery through search and retrieval. They are used in metadata systems, catalogs, and search interfaces to help users locate relevant materials.

Indextermen can be drawn from controlled vocabularies, such as thesauri and subject heading schemes, or they can be free-text keywords chosen by indexers or authors. Controlled terms provide consistency and disambiguation across a collection, while free-text terms can better reflect user language and newly emerging concepts. In practice, many systems combine both approaches to balance precision and recall.

In metadata records, indextermen appear in fields such as subject, keywords, or descriptors. Thesauri and vocabularies often define relationships among terms, including broader terms, narrower terms, and related terms, which supports both direct searching and navigational browsing. Multilingual vocabularies and translations further enable cross-language discovery.

The use of indextermen offers several benefits: improved recall and precision, better navigation within collections, and enhanced interoperability across systems that share common vocabularies. Challenges include maintaining consistency across large or evolving collections, managing synonyms and homographs, and ensuring adequate coverage for different disciplines and languages. Regular curation and governance are typically required.

In practice, libraries, archives, and digital repositories rely on indextermen as a core component of subject indexing workflows. They are often associated with standardized vocabularies such as Library of Congress Subject Headings (LCSH) or domain-specific schemes like MeSH, among others.