The present study proposes and examines the multidimensional vector (MDV) model framework as a modeling schema for choice response times. MDV extends the Thurstonian model, as well as signal detection theory, to classification tasks by taking into account the influence of response properties on stimulus discrimination. It is capable of accounting…

The coincidence hypothesis predicts that dissimilarity between objects that differ on two separable dimensions is larger than predicted from their unidimensional differences on the basis of triangle inequality and segmental additivity. The coincidence hypothesis was supported in two-dimensional stimuli studies. (Author/CM)

A rational model of human categorization behavior is presented that assumes that categorization reflects the derivation of optimal estimates of the probability of unseen features of objects. A case is made that categorization behavior can be predicted from the structure of the environment. (SLD)

A model of category effects found in reports of episodic memory is proposed. The model holds that stimuli are presented at a fine-grain level of detail and a category. Four experiments involving a total of 131 University of Chicago (Illinois) students and faculty are reported in support of the model. (SLD)

The developmental trend from overall-similarity to dimensional-identity classifications is explained by a quantitative model. The model provides good qualitative fits to the extant data. Three experiments examining classifications in 120 2- to 8-year-olds and in 20 undergraduates support specific new claims of the model. (TJH)