A study of the ability of young children to discriminate among such letters as p and q, d and b, using four different methods of discrimination (matching, copying, naming, and writing to dictation). Results show that the accuracy of discrimination is dependent upon the method of assessment employed. (Author/WY)

Three groups of severely retarded and three groups of mildly retarded individuals responded to a series of five 10-trial oddity problems under nonreward conditions. Results suggest that oddity is a stimulus characteristic to which an approach response is made, independent of its concurrent association with reward, and that stimulus value of oddity…

The ability of preverbal infants to form and use ill-defined categories, to respond differentially to contrasting categories, and to use specific dimensions in learning these categories is examined in 20 infants 10 months of age. Results show that infants are not only capable of learning two ill-defined categories, but that they can do so with…

Visual preference and habituation paradigms were used to investigate the ability of three-month-olds to recognize the photographed face of the mother and to discriminate it from another face. Infants discriminated between the pictures of the mother and a stranger, both in the preference test and in the recognition test after habituation.…