The last chapter showed us that the thesaurus is very much a multipurpose vocabulary tool. As a consequence it has a number of potential applications, some of which have arisen only recently, within the context of electronic information management. In this chapter we will look at the ways in which the thesaurus can be used, primarily by the information professional for indexing and the organization of information, but also by the end-user to support retrieval through searching and browsing.

The thesaurus as an indexing tool

As it was first developed, the thesaurus was an indexing tool for large technical document collections; that is to say it was used as a source of descriptors or indexing terms for attaching to the database or catalogue records for those documents. These assigned index terms would then form the ‘text’ which was searched in subject searches. Used in this way, the thesaurus almost presupposes the machine management of document collections.

Thesaurus terms for subject headings

In fact the thesaurus can be used equally well in a print-based environment if the terms are combined to create alphabetical subject headings. A thesaurus used in this way will require clear instructions for the combination of terms, particularly for the order in which terms should be combined, if consistency is to be maintained. A good example of this sort of application of a thesaurus is in the paper version of Library and Information Science Abstracts(LISA)where ‘every abstract in LISA is indexed with a general term taken from the LISA Thesaurus,to which qualifying terms are added to increase the specificity of the string’.1 In other words, the thesaurus terms are combined to create subject headings for the printed list, as in this example, taken from the November/December 2005 edition of LISA :