The quest for determining the degree of learning difficulty associated with different types of categories has been instrumental in our understanding of human categorization behavior and, more broadly, human generalization. For instance, we now know that the topological nature of the dimensions (e.g., whether these are integral or separable) that…

The findings of Shepard, Hovland, and Jenkins (1961) on the relative ease of learning 6 elemental types of 2-way classifications have been deeply influential 2 times over: 1st, as a rebuke to pure stimulus generalization accounts, and again as the leading benchmark for evaluating formal models of human category learning. The litmus test for models…

This paper presents the empirical basis for the phenomena known as stimulus overselectivity. Stimulus overselectivity involves responding on the basis of a restricted range of elements or features that are discriminative for reinforcement. The manner in which such a response pattern impedes the skill acquisition in children is identified. A…