Testing Genre and Form Term Mapping between the Library of Congress Subject Headings and Library of Congress Genre/Form Terms for Automatic Metadata Enhancement

The American Library Association Core Subject Analysis Committee Subcommittee on Faceted Vocabularies (SSFV) works to advance retrospective implementation of genre/form terms and other faceted metadata in library catalogs. This has included publishing a set of modular best practices for librarians and programmers that comprises specific mappings between Library of Congress Subject Headings (LCSH) and other MAchine-Readable Cataloging data and their corresponding terms in faceted vocabularies. SSFV expects to expand these best practices through successive releases and since 2022 has engaged in testing of its LCSH–to–genre/form term mappings in order to refine them on an ongoing basis. Early rounds of testing helped SSFV identify mappings where human evaluation was needed beyond initial expectations and highlighted the inconsistency of original metadata, underscoring our awareness that mappings are only as useful as the data of the original record. This article discusses the issues of data variance and mapping reliability further and analyzes each in detail. It provides an overview of SSFV’s involvement in the development of genre term vocabularies and then discusses the process of mapping development, patterns identified in this process, and the testing procedures, results, and outcomes to show how the evaluation of genre term mappings can inform other types of faceted vocabulary mapping in the future.