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November 09, 2005 [posted]

New Authority Index Feature in the NLM Catalog

NLM® is pleased to announce the implementation of a new authority index1 feature in the NLM Catalog. This new feature provides access to an index of full author names (including dates and name qualifiers), organizations, and conference names, as well as series titles, associated with the bibliographic records in the NLM Catalog.

The authority index also offers added value by incorporating rich cross-reference entries for variant forms of names and titles that lead the user from a raw, initial search to the established form used on bibliographic records in the NLM Catalog. It also supports searching of names that may have changed over time, providing links to other and historical names used by authors or organizations, and to conference names and series titles that have changed numerous times. For series titles, additional information regarding NLM bibliographic treatment of that series is also provided (see Display of Series Information below).

Using the Authority Index

Click on the new "Authority Index" tab that appears to the right of the "Details" tab. Enter the name (which can include personal, corporate or conference names) or series title as an untagged search in the new search box that is displayed. Search personal names by entering "last name, first initial"; search corporate or conference names and titles by entering the first known portion of the name or title. The authority index is not text word searchable. Click the box labeled "Search" to invoke the search of the index (see Figure 1).

Optionally, enter a name of a person, organization, conference, or series title into the main search box, tagged by [ai]. When this is done, the system automatically invokes the "Authority Index" tab and the search also appears in the authority index search box.

Results of a Search of the Authority Index

A search of the authority index results in an alphabetic display where the established form of a name or title is hyperlinked and appears in blue type. As an example, the search of the name "smith, j" results in the display shown in Figure 2. Here, the name "Smith, J Barker" is the established form of interest and the name is linked; clicking on this link retrieves the bibliographic record(s) associated with that name in the NLM Catalog (see Figure 3).

The authority index provides for more specificity in an NLM Catalog search. As an illustration, compare the focused retrieval where using the authority index by clicking on the desired link results in retrieval of a single bibliographic record associated with the name "Smith, J Barker" (see Figure 3) to a search of the name as an author where twenty-six (26) bibliographic records need to be examined to determine the one desired (see Figure 4). When a search on the desired established form is done, the system automatically enters a number with the search tag for the authority index id [aiid] in the main search box.

Using the Power of Cross References in the Authority Index

As previously described, the authority index also provides access to cross-reference entries for variant forms of names and titles that can assist the searcher in identifying the form used in NLM bibliographic records and improve the success and exactness of retrieval. Additionally, links are provided to the different forms of a name or series title that may have changed over time.

Searching Variant Forms
Variant forms appear before the word "see," appear in black type, and are not linked. As an example, the authority index display in Figure 2 above includes an index entry for "Smith J A R (John A R)" that is not linked, representing a variant form used by the author. The user is led from this other, variant form to the established form of the name (appearing after the word "see") that is linked. In this case, the established form of the name is "Smith, John A R." When a user clicks on the link for the established form, that form appears in the authority index search box and at the top of the authority index (see Figure 5). Clicking once again on the link "Smith, John A R" in the authority index retrieves all bibliographic records associated with that established name.

Using Links to Other Forms
The authority index also provides links to earlier, later, and related forms of names and titles, identified by the label "see also." This is particularly useful to searchers, providing links to other names used by persons over time, historical names of organizations, and changes in titles of series.

For example, to search the government name "United States. Dept. of Education," enter that phrase in the authority index search box (see Figure 6). When the authority index is displayed, not only does the name searched appear, but there are also links to other forms used by that organization. All established forms used by the organization appear after the phrase "see also" and are linked. Clicking on these established forms leads the user to the bibliographic records associated with those names.

Display of Series Information

When a series title is searched in the authority index, the display of the series title is prefaced by a plus sign (+) and the label, "Series title: ," with the title of the series appearing alphabetically (see Figure 7).

Clicking on the plus sign reveals additional information related to the NLM treatment of that series title (see Figure 8). The information provided includes the NLM analysis practice, classification practice, and classification number (when present). These data appear labeled as below:

Analysis Practice: Identifies whether the series title is analyzed at NLM (i.e., whether a user can expect to find separate bibliographic records in the NLM Catalog for individually titled volumes that are part of a series); parenthetical information related to the analysis practice may also appear.
Classification Practice: Identifies whether the series title is classified together in one classification number or whether each bibliographic record in that series is given a unique subject-oriented classification; parenthetical information related to the classification practice may also appear.
Classification Number: Identifies the NLM classification number assigned (when one is available)

Special Considerations

For additional information, see the Help on the NLM Catalog.

1 Note: The authority index contains only names and titles that have corresponding bibliographic records in the NLM Catalog; for access to the entire NLM authority file or for access to MARC 21 formatted authority records, use LocatorPlus at

By Alice E. Jacobs
Cataloging Section

Jacobs AE. New Authority Index Feature in the NLM Catalog. NLM Tech Bull. 2005 Nov-Dec;(347):e4.

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