ABSTRACT
Many kinds of structure can be discerned in the headings and rules governing the Library of Congress Subject Headings. By addressing these structures at different levels, librarians can develop different approaches to the machine-assisted validation of subject headings, from the checking of individual words to the validation of complex forms of heading/subdivision compatibility. Using computer programs to assist with maintenance of subject headings is becoming increasingly necessary as technical services librarians strive to create consistent and useful patterns of subject collocation in library catalogs. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: <getinfo@haworthpressinc.com> Website: <https://www.haworthpressinc.com>]
