An exploratory study probed the extent to which children rely on category membership to guide their inferences. A total of 60 children, 4 years of age, were shown 20 sets of pictures of various animals, plants, and minerals. Each set consisted of representations of three objects having two salient features: perceptual similarity/dissimilarity and…

Three studies investigated the effects of concrete versus abstract wording and negative versus positive premises on the difficulty subjects had in solving several kinds of reasoning tasks. Subjects for all three studies were college undergraduates who received booklets containing either hypothetical, disjunctive, or linear syllogisms. Each booklet…

To investigate the origins and nature of intuitive obstacles affecting the learning of elementary probability theory, 618 Italian elementary and middle school students were interviewed about their methods of solution for several problems dealing with probability. The discussion focuses on four varieties of obstacles to learning prevalent within…