Authority Control
What is Authority Control?
Bibliographic control in a library catalog is accomplished by the assignment of a unique form of a heading and the use of cross-references from unused and related headings. Selecting a single form brings together in one place all the works of an author, editions of a work, titles in a series, and subjects dealing principally or exclusively with a topic. Through the use of see and see also references, authority control creates a syndetic structure that guides the user to the materials sought. The see reference tells the user that the information being sought is to be found not under that heading, but rather under a different (i.e., the "authorized") heading. See also references show relationships between headings. The two concepts of heading uniqueness and cross-referencing are the pillars of authority control. Together they make possible efficient access to library resources.
Why has authority control become increasingly important to libraries? In the past, library administrators have viewed authority control as a desirable element in the cataloging process, but one so costly in professional staff time as to be justifiable only in research institutions. These days the ubiquity of Library Management Systems (LMS) in all types and sizes of libraries belie the notion that authority control is a luxury.
Widespread implementation of on-line catalogs reveals what card catalogs so effectively concealed. Namely, that most card catalogs were plagued with "divided file" headings, archaic subject terms and place names, non-existent or inadequate cross-references, and otherwise misleading headings. Changing cataloging rules, reliance on shared cataloging from bibliographic utilities, and, until recently, the catalog's physical form, have all contributed to the problem of maintaining current and consistent name and subject headings. Many of the problems found in card catalogs were carried over into online catalogs, particularly if the library's records were never authorized, or authorized poorly.
Fortunately, Online Public Access Catalogs (OPACs) not only reveal problems that remained hidden in card catalogs, but the machine-readable records from which the LMS is created make possible a level of authority control superior to anything that could be achieved in non-computerized catalogs.
Authority control is essential for effective local system searching. It improves access dramatically by providing consistency in the form of headings used to identify authors, place names, uniform titles, series, and subjects. Equally important are logical linkages between names and concepts. Keywords, combined with Boolean operators, offer powerful supplemental search capabilities, but they are no substitute for authority control. The collocation functions of a library catalog go well beyond its "finding list" functions and can only be met by traditional authority control.
Although library users are the principal beneficiaries of enhanced access resulting from authority control, authorized headings and display of cross-references within a local system reduce the work of technical services librarians responsible for building and maintaining the catalog. There is a price to be paid for good authority control, but an even bigger price to be paid for not having good authority control. Participation in resource sharing networks, cooperative ventures such as NACO, dependence on Internet connectivity, and recent trends in "outsourcing" technical services operations are also strong arguments for libraries to ensure headings adhere to national bibliographic standards. An ancillary benefit of authority control is the imposition of consistency on variant forms of the same heading that fail to link to an authority record.