ABSTRACT
Related terms: Flight As a further illustration of how such an authority list might be used, let us take, for example, a library catalogue. In this type of system, when the subject of a document, or some other record, has been ascertained, instead of, or as well as, translating this subject into a classification number, alphabetic indexing terms that succinctly and specifically describe the subject will need to be selected. An examination of a particular document, for instance, might reveal that it is concerned with the subject ‘Wages of post office workers’. Using ‘natural’ language, that is, terms taken directly from the document, the terms that describe the subject are:
Wages Post office Workers
If a natural language index is all that is required, then these are the terms that would be used but if consistency is the aim, then an appropriate
‘authority list’ must be consulted. This may well instruct that ‘Post office’ is acceptable but that ‘Remuneration’ is to be preferred to ‘Wages’, and ‘Personnel’ is to be preferred to ‘Workers’. The terms that must be used are therefore:
Remuneration Post office Personnel
The indexing language is being ‘controlled’ so that the same subjects are consistently indexed under the same terms. Today, such a structured, controlled vocabulary or indexing language is more often referred to as a ‘thesaurus’. Here is a typical entry from a published thesaurus (Thesaurus, 1997):
Thromboses Broader Cardiovascular Disorders Narrower Cerebral Thromboses
Coronary Thromboses Related Embolisms
Clearly, in a similar manner to the illustrative entry for ‘Aviation’, hierarchical and coordinate relationships or groupings are being established, that is:
Cardiovascular Disorders
Thromboses Embolisms
Cerebral Coronary Thromboses Thromboses
Because the grouping of concepts in this way very obviously embodies a process of classification, can a classification scheme possibly provide a base from which to compile an alphabetically arranged thesaurus? The answer is a very definite ‘Yes’ and a faceted classification lends itself admirably to this process. The method helps to keep inconsistencies to a minimum and ensures that the thesaurus is grounded upon firm principles. If, for example, a classification scheme were being compiled for the subject ‘People’, then the facets would probably include:
People By age By sex By race Children Male European Adults Female Asiatic etc. etc. etc.
