In the preliminary stages in the construction of the thesaurus you have begun to assemble your vocabulary and you will have a number of terms. If you have followed the methods of vocabulary collection described, these have come from a number of different sources, and the style and form of the terms may vary quite a lot. The vocabulary is only at the first stage of being properly managed, and you should start to work towards a fuller level of standardization.

Creating a list of standard terms (that is, a vocabulary) for indexing requires the compiler to do several things:

This process is even more important when any degree of automation is involved, since the search software will demand (nearly) exact matching between indexing and search terms if retrieval is to occur at all. Although the development of fuzzy searching systems allows some variation in terms (such as a mistyped letter), the form of terms still needs to be very close to the original to get a result.

All of the above actions together constitute what is known as vocabulary control. You will see that there are two main aspects of this process:

The selection of terms

Synonym control: preferred and non-preferred terms

Synonymy, that is the occurrence of a number of different words for the same idea, creates considerable problems for the online searcher. In a system such as a classification scheme, where notational codes are used to represent concepts, the existence of different names for the same idea doesn’ present a problem, since the notation equates to as many words as necessary and acts as a kind of shorthand for the concept.