Thesaurus Construction

Thesaurus construction is the systematic building of a controlled vocabulary in which preferred terms are linked by a standardized set of relationships — equivalence, hierarchy, and association — to support consistent indexing and effective retrieval. The definitive practical methodology was set out by Jean Aitchison, Alan Gilchrist, and David Bawden in their manual Thesaurus Construction and Use, and the controlling standard in the United States is ANSI/NISO Z39.19, with ISO 25964 as its international counterpart. A thesaurus collects the terms a domain uses, resolves synonyms and homographs so each concept has one preferred label, and then wires the preferred terms together with USE/UF, BT/NT, and RT relationships plus scope notes. The result is a structured map of a subject's concepts that indexers and searchers share, reducing the mismatch between the words authors, indexers, and users choose.