Whats a thesaurus?
A thesaurus is a type of controlled vocabulary, a collection of terms. Terms represent concepts, but it is the concepts themselves and their relationships, not the terms, that constitute the thesaurus. Terms are related to one another in three different ways: Hierarchy A term always has an “is a” relationship with its broader term (BT); a narrower term (NT) can always be said to be “a type of”, “a part of”, or “an instance of” the parent term. Preference For a given concept, one term is chosen as the preferred term or label, and is referred to as the descriptor. Other terms that refer to the same concept are referred to as lead-in terms or non-preferred terms. A non-preferred term is not necessarily a synonym of the preferred term. Generic relationships Where concepts are related in some way that cannot be expressed as an “is a” sentence, the thesaurus simply connects one term to another without specifying the nature of the relationship. This is different from more elaborate knowledge-
