Library of Congress Subject Headings (LCSH)

The Library of Congress Subject Headings (LCSH) comprise a thesaurus of subject headings, maintained by the United States Library of Congress (LC), for use in bibliographic records.


The Library of Congress applies the principle of literary warrant:


"The Library of Congress collections serve as the literary warrant (i.e., the literature on which the controlled vocabulary is based) for the Library of Congress subject headings system. The number and specificity of subject headings included in the Subject Authority File (the machine-readable database containing the master file of Library of Congress subject headings from which the printed list, the microform list, the CDMARC SUBJECTS, etc. are generated), are determined by the nature and scope of the Library of Congress collections. Subject headings are established as they are needed to catalog the materials being added to the collection or to establish links among existing headings. In recent years, headings contributed by libraries engaged in cooperative activities with the Library of Congress based on the needs of their collections have also been included.

3.2 References:

point_bl.gifH 187 When To Establish A New Heading:

"Establish a subject heading for a topic that represents a discrete, identifiable concept when it is first encountered in a work being cataloged, rather than after several works on the topic have been published and cataloged."

point_bl.gifH 198 Creating Authority Records For Headings Formerly Unprinted In LCSH (p.2):

"If, in establishing a new heading or in creating an authority record for a heading that previously had none, it is necessary to use, as a broader term in a 5XX field, another heading that lacks an authority record, prepare an authority worksheet also for the heading needed for use as a broader term...Continue upward in the hierarchy in this manner until no additional headings lacking authority records are encountered.""


Criticism of LCSH

Svenonius and McGarry (1993) conducted research with the hypothesis that there is a “clear-cut right and wrong to LCSH subject heading assignment” at least 80% of the time. In a study of 100 books they found that objectivity in assigning subject headings is possible. Their recommendations to increase subject heading consistency include improving the syndetic structure of LCSH, increasing scope notes, and providing better training and education for subject catalogers.


"Kirtland/Cochrane [Kirtland & Cochrane, 1982, p. 83] noted in the first critical LCSH bibliography: there is “hardly a group of scholars representing various disciplines that has not complained about LCSH’s lack of adequate and detailed terminology.”  The complaining continues three decades later. Whitehead, Kim, Studwell, Clack, Copeland, Colby, Cheng, and Wilk all address the problem of LCSH not having specific enough terminology for the needs of certain disciplines. As disciplines and areas of research become specialized or interdisciplinary, the problem of the lack of specificity in LCSH is compounded." (Fischer, 2005, p. 79).


"The literature from 1990-2001 clearly indicates that LCSH needs to be amore useful subject access tool. LCSH must become more flexible, efficient and easier to use in order to increase its scalability, interoperability and adaptability. It is useful to revisit the concluding remarks from the previous two bibliographies because they show that for more than two decades users of LCSH had been petitioning the Library of Congress to make the list more progressive. Kirtland and Cochrane [1982, p. 90] concluded after reviewing the literature up to 1979: “It seems clear from this review of the criticism that the Library of Congress, if it wishes to maintain a useful tool in the computer age, has to do something, which involves ‘major revision.’” However, Shubert [p. 84] states, in response to Kirtland and Cochrane and to the literature of the 1980s: “With or without major revision, LCSH will be the major tool for subject access to North American library collections for the forseeable future.” " (Fischer, 2005, p. 103).


Dykstra (1988) writes that LCSH in 1986 began to use new codes to show the cross reference structure. The codes, the adopted was the standard codes of a thesaurus (USE, UF, BT, NT, RT). By adopting those codes, the LCSH now became "thesaurus-like". However, by doing this the LC Cataloging Division violated nearly all international standards and guidelines for thesaurus construction.


Drabenstott & Vizine-Goetz (1994) is a carefully researched book about LCSH. Chapter 3 mentions the sparseness of subject terms in bibliographic records, and in Chapter 4 is described the low level of compatibility between subject headings in the bibliographic file and those in the authority file. In essence, the large numbers of subject headings assigned in bibliographic files that are not compatible with those in the authority file over the years has made the LCSH authority file less useful a tool in interface design to improve subject access, and the poor match between the two contributes greatly to the failure in users’ queries.


"I am not suggesting that we force Library of Congress Subject Headings (LCSH) onto the federal Web pages. The LCSH were a nineteenth century solution to nineteenth-century problems. It is time to fundamentally rethink our approach to the whole issue of controlled-vocabulary access systems and apply that new thinking to provide access to the Web.’’"  (Miller, 2003, p. 2816).


Larson (1991) found that the use of subject searching tend to decline because of problems associated with LCSHs.





Berman, Sanford (1971). Prejudices and antipathies: a tract on the LC subject heads concerning people. Metuchen, NJ: Scarecrow.

Chan, L. M. (2005). Library of congress subject headings: Principles and application. Fourth Edition. Westport, Conn. : Libraries Unlimited.  (Library and Information Science Text Series)


Chaplan, M. A. (1995). Mapping Laborline-thesaurus terms to Library of Congress Subject Headings: Implications for vocabulary switching. Library Quarterly, 65(1), 39-61. 


Drabenstott, K. M. & Vizine-Goetz, D. (1994). Using Subject Headings for Online Retrieval: Theory, Practice, and Potential. San Diego: Academic Press.


Dykstra, M. (1988). LC Subject-Headings disguised as a thesaurus. Library Journal, 113(4), 42-46


Fischer, K. S. (2005). Critical Views of LCSH, 1990-2001 The Third Bibliographic Essay. Cataloging and Classification Quarterly, 41(1), 63-109.


Kirtland, M. & Cochrane, P. (1982). Critical Views of LCSH–Library of Congress Subject Headings, A Bibliographic and Bibliometric Essay. Cataloging & Classification Quarterly 1(2/3), 71-94. 


Larson, R. R. (1991). The Decline of Subject Searching: Long-Term Trends and Patterns of Index Use in an Online Catalog. Journal of the American Society for Information Science, 42(3), 197-215.

MacEvan, A. (1998). Working with LCSH: the cost of cooperation and the achievement of access. A perspective from the British Library. 64th IFLA General Conference August 16 - August 21, 1998.


Miller, U. (2003). Thesaurus and New Information Environment. IN: Encyclopedia of Library and Information Science. New York: Marcel Dekker. (Pp. 2811-2819).


Shubert, S. B. (1992). Critical Views of LCSH–Ten Years Later: A Bibliographic Essay. Cataloging & Classification Quarterly, 15(2), 37-92.


Stone, A. T. (Ed.). The LCSH Century: One Hundred Years with the Library of Congress Subject Headings. New York: Haworth Information Press. Also published simultaneously as a special issue of Cataloging & Classification Quarterly.

Svenonius, E. & McGarry, D. (1993). Objectivity in Evaluating Subject Heading Assignment. Cataloging & Classification Quarterly, 16(2), 5-40.


Whitehead, C. (1990). Mapping LCSH into Thesauri: The AAT Model. IN: Beyond the Book: Extending MARC for Subject Access, eds. Toni Peterson and Pat Molholt, Boston: G. K. Hall, p. 81-96.


Wikipedia. The free encyclopedia. (2006). Library of Congress Subject Headings.


Fundamental principles of Library of Congress Subject Headings:


See also: Library of Congress Classification (LCC); Subject heading



Birger Hjørland

Last edited: 22-12-2007