Authority Control

Steps in Authority Control

Authority control generally takes place following all other database work, e.g., duplicate record resolution, creation of item fields. Libraries migrating from one local system to another often take this opportunity to re-authorize their bibliographic records and obtain up-to-date authority records prior to loading records into the new local system.

From a processing perspective, batch authority control is achieved through a series of clean-up operations. First, headings are "normalized" for spacing and punctuation to increase the probability of a link between a catalog record heading and an authority record heading. Next, the normalized headings are compared against a comprehensive index of authorized and variant-form headings generated from authority records. When a match occurs, a link is created between the authority record heading and the catalog record heading. If the catalog record heading matches a see reference (tag 4XX) in an authority record, the catalog record heading is replaced by the contents of the authorized heading in the authority record (tag 1XX).

Ideally, all headings in the library's database should match an LC authority record, but in practice some headings do not link. The vendor responsible for authority control must do everything possible to increase links between catalog record headings and authority records while avoiding false matches.

After all possible headings are matched to an authority record, they are inserted back into the bibliographic records. That is, the authority record heading replaces completely the bibliographic record heading. Along with the post-processed database of bibliographic records, the linked LC authority records are extracted and returned with the bibliographic records for loading into the local system's authority module. Authority records returned to the library are collection-specific. The local system builds its index tables from both the controlled headings in the bibliographic records and the see and see also cross-references present in the LC authority records.

The number of bibliographic records returned is the same as the number of source records to be authorized. Prior to loading the new, comprehensive replacement authority records, the library will want to delete all existing LC and local authority records. In other words one wants to "overlay" the newly authorized catalog records, while authority records need to be completely replaced. During the period while the database is being authorized staff may continue to catalog new titles; however, they should avoid making changes to existing catalog records. This restriction does not apply to item record data-e.g., location codes, barcode numbers, etc.

Depending on the local system, the library may want brief or "provisional" authority records created for headings either not matching, or not fully matching, an LC authority record. These are skeleton authority records containing the unverified heading and default data. Provisional authority records do not contain cross-references and are of limited use since most modern local systems are capable of generating such authority records from unlinked headings.

Following batch authority control, a library is confronted with two challenges in keeping its catalog headings up-to-date and consistent. The first is to ensure that headings from new catalog records being added to the database are authorized. Options for controlling new headings include: 1) authorize them manually at the time of cataloging prior to loading the new bibliographic records into the database; 2) make no attempt to authorize new headings at the time of cataloging or record load, but periodically export and submit newly added bibliographic records to the authority control vendor for batch authority processing; or, 3) use a FTP-based service to transmit new records to the authority control vendor in batches on a regular (e.g., weekly, biweekly) or irregular basis.

A second challenge in keeping a library's headings in harmony with authorized headings is controlling for new and revised authority records issued after the library's records were batch processed. To help catalogers keep abreast of these additions and changes, authority control providers offer services alerting customers to the issuance of new and changed LC authority records affecting headings in the library's database.

Unless the library views authority control as a one-time event (i.e., it has no interest in maintaining control over headings after the batch authority control is finished), the availability of a comprehensive update service should be an important consideration when selecting an authority control vendor.

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