A turning point in mathematical learning theory.

This target article by Estes (1950) sparked the mathematical learning theory movement, which took seriously the goal of predicting quantitative details of behavioral data from standard learning experiments. The central constructs of Estes's theory were stimulus variability, stimulus sampling, and stimulus-response association by contiguity, all cast within a framework enabling predictions of response probabilities and latencies. The math models enterprise flourished during the period 1950-1975 and provided successful quantitative accounts of data from Pavlovian and instrumental conditioning, probability learning, verbal learning, concept identification, and other standard learning paradigms. The techniques have been assimilated into the armamentarium of theoretical psychology. Stimulus sampling theory has faded away as it has been transformed into modern descendants such as connectionism and information-processing models of cognition.