Controlled Vocabularies...hmmm

What is a 'controlled vocabulary'?

As we all know, language is imprecise. Even in science and medicine where you'd think language would be extremely precise, concepts are represented by a variety of words and phrases. For example, look at all the different words you can use to describe 'adolescence':

teenagers, teenager, teens, teen, adolescent, adolescents, adolescence, young adult, young adults, youngster, youngsters, 13 year old, freshman, freshmen, 9th grader, etc.

A controlled vocabulary is a standardized collection of terms -- each term represents a concept or a subject. The term is usually defined, examples and other pertinent information are provided all in an effort to reduce ambiguity.

Most controlled vocabularies or thesauri will show the relationships between words through hierarchical relationships (broader terms, narrower terms), see related cross references (other related terms which may be of interest) and see cross references (link to an appropriate term from common synonyms or from an unused more specific term).

In MEDLINE, the Medical Subject Headings (MeSH) is the controlled vocabulary. The indexers who read and analyze the journal articles assign MeSH terms to describe the subject content of the article. Usually an article will have approximately 10-12 controlled vocabulary terms assigned.

Examples of Controlled Vocabularies:
Thesaurus of Psychological Terms[PsycINFO]
Medical Subject Headings (MeSH)[MEDLINE, CINAHL]
Library of Congress Subject Headings [Online catalogs]
Phone Book Yellow Pages