About Thesauri

© 2000. Jessica L. Milstead. All Rights Reserved

What is a thesaurus?

For more information on what an information retrieval thesaurus is and what it contains, see the American standard for thesauri: National Information Standards Institute. American National Standard Guidelines for the Construction, Format, and Management of Monolingual Thesauri. Bethesda, MD: NISO Press, 1994. (ANSI/NISO Z39.19-1993). While standard thesauri are formalized and highly structured, for some purposes a less complex vocabulary is adequate.

When does my organization need a thesaurus?

What can a thesaurus do for me and for my organization?

Properly developed and used, a thesaurus can play several roles:

What about using an existing thesaurus?

If I decide to build my own thesaurus, how do I go about the process?

In addition to the ANSI/NISO standard, the best guide to development of a thesaurus is: Aitchison, Jean & Gilchrist, Alan. Thesaurus Construction: A Practical Guide. 3rd ed. London: Aslib, 1997. (Available from Portland Press).

There are two basic methods for building a thesaurus: "top-down" and "bottom-up." In real life most thesaurus development efforts are a mixture of the two.

The top-down method:

The bottom-up method:

Maintain your thesaurus. A thesaurus is never "finished," unless it is no longer being used for indexing or its database is no longer being updated. Plan for maintenance before you even begin developing your thesaurus. A thesaurus which is not well-maintained quickly becomes a liability rather than an asset.

What about software?

If you are thinking about using database software you already have, or even building a thesaurus using word processing software, DON'T. Even a small thesaurus will represent a very large investment of time and intellectual effort. Software which will automate the clerical and repetitive tasks is available for a cost that is very reasonable when you consider the true cost and value of the tool you will be producing.

A listing of some of the thesaurus management packages which are on the market today follows. Do not misinterpret statements about "has a thesaurus" in the publicity for packages designed for other purposes such as retrieval or library automation. Many of these do not manage a thesaurus; they simply provide access to a thesaurus file that is read in from another resource.

Standalone packages

Except as noted, these packages run on PCs and/or are available via the Web. Some also run under Unix; check with the vendors for specifics. 

Data Harmony
Term Tree 2000
Thesaurus Builder

Database modules

In general, these modules are integral parts of the larger system, and cannot be run separately. Their availability may vary, depending on the vendorís development priorities.

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