Proceedings of the Annual Meeting of the Cognitive Science Society

Anderson and Milson (1989) derived optimal performance functions for memory based on assumptions about the goals of memory, the computational costs of achieving those goals, and the statistical structure of the environment. Based on these assumptions, and a good deal of Bayesian analysis, they accounted for a substantial number of empirical findings. Here we started with the same assumptions about the goals of memory, but instead of simulating the statistical structure of the environment, we analyzed it directly. It was found that the factors that govern memory performance also predict the probability with which words are spoken in children's linguistic environments. These factors include frequency, recency, and spacing between exposures. The ability of these factors to predict word use was analyzed in the context of four laboratory memory phenomena: 1) the power law of practice; 2) the power law of forgetting; 3) the interaction between study spacing and retention interval and 4) the combined effects of practice and retention. These factors predict information demand and lend strong support to Anderson and Milson's claim that memory behavior can be understood in terms of the statistical structure of the environment.