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October - December 2009     VOLUME 13 ISSUE 4
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Behind the scenes @ the library

Subjects in the Online Catalog
Donna Gray-Williams

How are the subjects selected for the material in the online catalog?

The idea behind the way we choose subject headings is for them to be consistent and controlled. We use Library of Congress subject headings manuals or as we catalogers call them “The big red books” to choose subject headings. Ideally, that means the same terms will be used all the time, and when you search for a subject everything the library has on that subject will show up under that subject heading.

Unfortunately, that doesn’t always work. The standard Library of Congress rule we follow for selecting subject headings is to choose the most specific term that fits the subject matter of the item in hand. That means if you have a book that deals in many different subjects or many facets of a subject, it has to go under a more general term, because the other standard Library of Congress rule we follow is to provide the fewest number of subject headings for any given item.

We use cross-references so if you think of a subject the Library of Congress doesn’t use there should be a reference to the one that is used. One example is the term Pigs. The Library of Congress uses Swine. When you search our catalog for Pigs it will say See related headings for Pigs. Click on Pigs and you will be cross-referenced to Swine.

If you search on a subject, find nothing, and don’t even get a cross-reference, let us know. Maybe it’s something we need to add as a cross reference. With hundreds of thousands of subjects in the database, it’s easy to miss a few.