Discussion of models for library circulation data highlights a new statistical prediction model that creates a flexible regression curve. Linear graphs that result from previous models are discussed, bivariate discrete distributions are explained, and graphs that show library circulation for one year at a time are presented. (nine references) (LRW)

Correlation structure of the Burrell and Cane mixed Poisson model for library loans with aging is presented and illustrated by data from University of Sussex. The approach is compared and contrasted with that originally formulated by Morse and recently reevaluated by Beheshti and Tague. Directions for future investigations are suggested. (Author)