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TL v56n2 Got Authorities? Why Authority Control is Good for Your Library
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Tennessee Libraries

Volume 56 Number 2



Got Authorities?

Why Authority Control Is Good for Your Library  


Kathleen L. Wells
Senior Catalog Librarian
University of Southern Mississippi Libraries


Author's note:  References to series statements in this article are applicable for libraries that intend, despite LC's recent decision on discontinuing series authority work, to continue providing controlled series access in their catalogs.

Presented as part of the program, "Got Authorities?"

Conference Abstract: This program will discuss the value of authority control in library cataloging, results of state and national surveys conducted on authority control and practices, and resources to assist in learning more about authority control work.

This paper will provide a brief overview of the value of authority control and will focus on ways in which certain fields in USMARC authority records interact with the online catalog to provide valuable information to catalogers and library users.

In a time of shrinking budgets and fewer staff, it can be difficult to justify authority control to administrators who have an eye on the bottom line. Authority control operates mostly behind the scenes. While library users can see MARC bibliographic records in the OPAC (even if the view of the records is abbreviated), authority control operates at a deeper level. Users see cross references that come from an authority record, and they search the headings that are authorized by that record—but they never see the record itself.

Another element in authority work is what we might call "scale." Hours of staff time may be required to produce a deceptively small product: a cross reference, a heading change, or a distinction between two identically titled series. But that seemingly small product can make a big difference in someone's success in finding specific information.

The time and cost factors involved in authority work make it one of those things that can be put on the back burner when other priorities arise, as they frequently do. Public desks have to be staffed, and library materials have to get to the shelves; library users are likely to complain if these things don't happen. If authority work isn't done, patrons may not find what they're looking for, but they don't know what they're missing or why. And when authority control does work, it works silently. Not many people find their way to the technical services area to congratulate us on our cross-references.

What Does an Authority File Do?

The work of an authority file can be summarized in a list of four functions (Block 1999):

  1. Authority function: authority control supports consistency of headings.
  2. Finding function: authority control provides links from variants and other authorized forms of headings. This is the cross reference structure.
  3. Information function: authority control shows usage and scope of headings. There are notes in the authority record that tell the user and/or the cataloger how the headings are applied.
  4. Maintenance function: authority control supports manual and automatic error detection and correction. This is carried out through the online system's identification of headings as unauthorized, and the library's efforts (through a vendor or by its own staff) to authorized the headings and make needed corrections.

But Can't I Find Everything with Keyword?

It is almost a cliché that authority control is unnecessary in an era of keyword and Boolean searching. However, browse searching linked to an authority control structure can provide information that is simply not available with other types of searches. Browse searches result in an index display, based on specific tags and subfields, that tells the user how many titles the library holds under a particular and precise heading. Since the display is a list of headings , the user also sees “see from” references (if he/she has chosen an unauthorized search term) or “see also” references to related headings (see Figures 1 and 2). Sometimes there will be a scope note that tells how a particular term is employed in subject headings. Without authority control, this reference structure would not exist.

Figure 1. Browse subject search under “Cookbooks” produces a clickable cross reference to the authorized term “Cookery”…


Figure 2. The cross reference leads the user to 268 records for cookbooks with the authorized subject term “Cookery,” plus a list of other possible authorized search terms at the right of the screen.

Keyword searching is also based on MARC in that the system is programmed to scan specific MARC fields, but with a keyword search, instead of a list of index terms, the user goes directly to a title list of records that contain the search term he/she entered. A keyword search can be broader or narrower than a browse, depending on its construction. Sometimes keyword searches are just what we need, as when we look up a conference or personal name that we're not quite sure of. But keyword searches do not provide references from the search term to other related terms, so a user looking up “Cookbooks” with a subject keyword search could miss most of the titles the library holds, since the authorized subject heading is “Cookery” (see Figure 3). A general or title keyword search on the term “Cookbook” could pull up many records, but would exclude those that used other title words such as “recipes” or “cooking” instead. We need both types of searches in our catalogs: users need keyword access to as many parts of the record as we can manage, and they need a structure that lets them select from a heading list that also refers them to related search terms.

Figure 3. Keyword subject search locates records with “Cookbooks” as a genre term from the Rare Books subject thesaurus—but not all the records with the LCSH authorized term “Cookery.”

The Rules Keep Changing

Keeping up with change in an online catalog is much easier with automated authority control. People and corporate bodies change their names. Subject headings are modernized or refined, as when a combined heading such as “Nurses and nursing” is split into two separate headings. And the rules themselves keep changing. We've gone from entering authors under their real names to using the form found on their works. The order of elements in conference headings has changed, along with the punctuation. Headings with geographic subdivisions are now subdivided indirectly. Geographic qualifiers have been added to the names of cities. Our ways of constructing entries for corporate bodies are now less hierarchical than they were. And big changes are not only a historical relic of AACR2 implementation: they continue to happen, such as LC's adoption of the Pinyin system of Romanization for Chinese characters in 2001. Subject heading changes that affect hundreds or even thousands of records can occur at any time.

There are also ongoing changes to the MARC format, as new tags are introduced and subfields changed to keep up with the growth of new material formats, such as electronic resources. Not many libraries have enough staff to keep up with such changes on a record-by-record basis as they occur. While authority control, strictly speaking, may not cover all MARC format changes, a vendor can make such changes to bibliographic records in conjunction with authorizing a library's database.

We're All Human

In addition to changes in the rules and the MARC format, online catalogs are subject to “quality drift.” Small errors, such as typos in capitalization or punctuation, accumulate over time. Occasionally the errors are not so small. While automated authority control won't create a perfect database, it can upgrade outdated headings and records, and a vendor's machine-matching process can pull errors like “Elementary school techers” and “Pumpkilns” into a report so that they can be corrected by library staff.

Types of Authority Records

The number of authority record formats has grown in recent years. In addition to the familiar name, title, and subject authority records, we now have records for topical and form subdivisions. Each of these record types may contain cross references or explanatory notes guiding catalogers in the creation and maintenance of authority records and/or OPAC users in constructing their searches.

100   Personal name
110   Corporate name
111   Conference name
130   Uniform title
150   Topical subject
151   Geographic subject
155   Genre subject
180   Topical subject subdivision
185   Form subject subdivision

While LC has not yet added genre subject authority records to its authority file, some libraries are creating them locally.

More than “See” and “See Also”

As mentioned above, the library user sees the results of authority control in standardized headings (tag 1xx), simple references to valid related terms (tag 5xx), and references that point him/her away from a heading that is not authorized (tag 4xx). But authority records can interact with the online catalog in quite a few other ways as well. The heading use codes in the fixed field of a MARC authority record are very significant in terms of how the authority file interacts with the OPAC. These codes tell the system if the heading is valid as a name, subject, or series. The name use fixed field is coded a (valid for use) not only for personal names, but for any headings that are appropriate for use as main or added entries. This means that in addition to personal, corporate or conference names, geographic headings such as the names of towns, and some uniform titles, such as the New York Times, will have code a in this field. If the heading is not appropriate for name use, it is coded b. The Subject Use field would be coded a not only for topical subject headings, but for any heading that can be used as a subject, including personal names. Depending on how a library's online catalog is set up, these fixed fields can control the cross-reference displays in the OPAC, preventing blind references. For example, if a library owns books by but not about an author, his/her authority record can be coded a for name use and b for subject use. Then any cross references associated with that name will display in an author browse search, but not a subject browse search.

Expanded Information

 In addition to referring users to related terms, MARC authority records contain codes that can expand into additional information in the displayed references in the OPAC. In corporate name headings, for example, the “see also” (510) references can be coded to tell the user that a related heading is an earlier or later form of the authorized heading in the 110 field:

110  2      Agricultural College of Pennsylvania
510  2      Farmers' High School of Pennsylvania |w a
510  2      Pennsylvania State College |w b

The a and b subfield codes tell us that these are, respectively, earlier and later valid headings for the name “Agricultural College of Pennsylvania.” In the online catalog, this information can display as a note:

For the heading Agricultural College of Pennsylvania
Search also under the earlier heading Farmers' High School of Pennsylvania
Search also under the later heading Pennsylvania State College

Similarly, codes in “see also” references in topical subject authority records (550 field) can display information on broader and narrower subject terms, corresponding to the BT and NT references in the Library of Congress Subject Headings:

150   Agriculture
550   Life sciences |w g
550   Aquaculture |w h

In this example, the g code indicates a broader term, while the h represents a narrower term. The online catalog can display this information as:

For the subject term Agriculture
Search also under the broader term Life sciences
Search also under the narrower term Aquaculture

Authority records for topical and form subdivisions can also have broader and narrower term coding in the “see also” references.

Explanatory References. Sometimes we wish to convey more information about a heading than can be contained in a simple MARC tag or subfield code. For these situations, the MARC authority format has complex reference fields that can display explanatory text to the user.

The 260 and 360 fields are used for complex “see” and “see also” references for subject authorities. One use of these fields is the provision of instructions on using search terms. Note that in such cases, the 150 field may not contain an authorized heading at all, but a term that cannot stand on its own, so that the authority record exists solely for the purpose of providing the explanatory information, which can be programmed to display as a textual reference in the online catalog. This example tells the patron (and the cataloger) how to use the term “Russian” in subject searches.

150      Russian
260      |i subject headings beginning with or qualified by the word |a Russian |i for works on topics pertaining to the Russian nationality, language, literature, etc.

The subfield a before the term “Russian” tells the system to put the term in the browse index, while the explanatory text in subfield i does not index. In the authority record fixed field, the “Auth Status” area would be coded n (instead of a) to indicate that the record is not for an authorized heading.

A complex “see also” reference in a 360 field refers the user to headings that begin with, or are subdivided by, terms related to the established heading in the150 field of the authority record:

150     Roads
360     |i  headings beginning with the words |a Road |i or |a Roadside

150     African Americans
360     |i  subdivision |a African Americans |i under individual wars, e.g. |a World War, 1939-1945--African Americans; |i and headings beginning with |a African American

The 663 and 664 fields contain complex “see also” and “see” references for name authorities. A 663 note can show complex relationships between personal names, as in the following example:

100 0    W. A. |c (Joint pseudonym)

500 1    Halasa, Pavol |w nnnc

500 1    Halasa, Ján |w nnnc

663       |a Joint pseudonym of Ján and Pavol Halasa. For works of these authors written under their own names, search also under: |b Halasa, Ján; |b Halasa, Pavol.

This record is for a joint pseudonym of two authors who have also published works individually. The explanatory note describes the relationship and tells us to search also under the authors' real names to find those works. The codes in |w at the end of the 500 fields indicate that the note in the 663 field takes the place of standard “see also” references. Note that the subfield coding for the indexed and non-indexed text in the 663 is different from the coding in the 260/360 pair—one of many ways the MARC format has of keeping catalogers on their toes.

A 664 “see” reference could be used for an explanatory note about an unestablished name heading (analogous to the 260 field for subjects). However, the Library of Congress instructs its catalogers to use 4xx fields on an established heading record whenever possible (Library of Congress, 1998, 664).

“Obsolete” But Still Useful

There are some fields that are no longer used by LC but which remain valid MARC tags. Two of these in particular may be useful to libraries wishing to display detailed local information to their users. The 665 history reference contained historical information for names, usually corporate bodies. This is where the entire name history of a body could be entered in an authority record and displayed in the OPAC, for example:

110  2   University of Southern Mississippi
665       |i Works by this body are found under the following headings according to the name used at the time of publication: |a Mississippi Normal College. |a Mississippi State Teachers College. |a Mississippi Southern College. |a University of Southern Mississippi .

The 678 biographical note field contained non-indexing information about the 1xx heading in the authority record:

110 2    Massachusetts Institute of Technology
678        Incorporated 1861.

100 1    Wallace, Anne
678        Head, Dept. of English, Univ. of North Carolina-Greensboro ; formerly Professor of English at the Univ. of Southern Mississippi .

Some information that was formerly included in the 678 field is now incorporated into the 670, the field that cites the sources consulted in establishing a heading—but the 670 is not a public display field, and the 678 can be configured to display in the OPAC. Libraries may wish to use the 665 and 678 to display information about, for example, local authors or corporate bodies.

A note of caution must be sounded when considering the use of fields that are not currently being entered into LC authority records: information in the fields could be lost if a locally enhanced authority record were overlaid by a “standard” authority record from a vendor or from the LC file. While the 665 and 678 can provide valuable information, managers may wish to reserve their use only for information of special interest to the library's users.

The 680 field is a note that is used to describe relationships among headings. Defined as a public general note, it can contain any information for public display that does not fit into any of the other defined note fields.

150     Industrial relations
680     |i  Here are entered works dealing with employer-employee relations in general. Works on that field of management which has the fundamental responsibility for recruiting, hiring, training, compensating, developing and caring for the general welfare of employees are entered under |a Personnel management. |i Works on the managing of employees by their supervisors so that duties are performed according to instructions are entered under |a Supervision of employees.

A version of this note, which is useful both to catalogers assigning subject headings and to users doing OPAC searches, appears on the subject authority records for all the terms referred to in the |a subfields.

There are, of course, many other MARC authority fields that provide valuable information to catalogers—but they are not configured for display in the OPAC. And a demonstration of the authority file's value to the catalog user may carry more weight in presenting the case for authority control to a skeptical administrator.

Worth the Trouble?

Authority work, for all its fine detail, isn't about perfection. It's more a matter of pursuing perfection knowing that we can never achieve it, but finding the effort worthwhile. New areas of knowledge open up all the time, generating a need for new subject headings or the revision of old ones. Titles, people and corporate bodies change their names. And unpredictable humans are the ones creating the bibliographic records, which can make for unexpected and possibly entertaining errors in our records. But our ongoing attempts to impose structure and order on this chaos fulfill the central role of our profession: helping library users get the information they need.


Block, Rick J. 1999. “Authority Control: What It Is and Why It Matters.” (accessed March 30, 2006).

Library of Congress. 1998. LC Guidelines Supplement to the USMARC Format for Authority Data. Washington , D.C. : Library of Congress.

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