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)

Reviews problems involved in analyzing data on educational or training needs and details use of the proportionate reduction in error (PRE) approach (Hildebrand, et al., 1977), which predicts the probability that certain combinations of a joint distribution will occur, then tests to see how closely the prediction matches the observation. (MBR)