The Brillouin Information Measure Applied to Materials Selection

This study addresses the problem of selecting materials for a subject collection in a university library. An objective, quantitative method was tested. It is based on the relationship of documents in a collection to a document considered for acquisition. The Brillouin formula was used to measure the impact of a document on the collection. It is an information measure which has been used to measure the order or disorder of a particular population distributed over a number of unique classes. In this application it is used to measure the diversity, or relatedness, of a collection of documents. "Comprehensiveness" is presented as a selection criterion; it is defined in terms of breadth of subject coverage, rather than number of documents in a subject collection. Implications for collection evaluation are discussed.