It is shown that Trueswell's empirical 80/20 rule arises from type of stochastic model for library loans presented by Burrell and Cane. Particular attention is paid to previously suggested uses of rule in identifying "core collection" for library noting that length of time period is of crucial importance. (20 references) (EJS)

Frequency-of-circulation distributions from 16 United Kingdom libraries participating in initial period of operation of the Public Lending Right are discussed. Differences between the libraries are highlighted, and, for each, the adequacy of various refinements of the simplest model (geometric distribution, negative binomial distribution, or mixed…

Utilizing 11 years of University of Saskatchewan circulation transactions, it is shown that P. M. Morse's Markov model of book use fits approximately 99 percent of data for whole collection and for three subject areas; contrary to his assumptions, one of the model's parameters is time dependent. Thirteen references are included. (EJS)

Library circulation records for five years in one Hawaiian elementary school were analyzed to discover patterns according to sex and grade level; identify titles, subjects, and types of books circulated; and determine circulation of Hawaiiana and books about Asia. Bibliography of 129 titles mentioned in text is included. (11 references) (EJS)

Describes a circulation model for academic research libraries which uses the mixed Poisson model, incorporating ageing of library materials, to predict future use of monographs and to suggest weeding procedures based on frequency of circulation. Longitudinal studies are examined and statistical details are appended. (Author/LRW)