Three key predictions of Piaget's groupement model of middle childhood cognition were examined in the speed and time concept areas with a total of 93 children in grades 1, 2, and 3. (ED)

Piaget's class-inclusion task was revised class-inclusion tasks were administered to 64 kindergarten and 64 first-graders. Each of the revisions enhanced performance as compared with Piaget's standard procedures. These results are considered in terms of two possible interpretations. (Author/SDH)

Notes that the Piagetian perspective admits the existence of interindividual differences but interprets them as noise masking the universal logical succession of structures, whereas the differential perspective views development as consisting of "vicarious processes." Asserts that the main aim of the "procedural studies"…

An investigation of Piaget's theory of object concept development through a series of six tasks administered in a combined longitudinal/cross-sectional design (which incorporated a number of methodological controls). Subjects were 36 infants who received the six tasks during each of three testing sessions over a 6-month period. (Author/ED)

Children in grades 1, 3, and 5 and college students were given a variety of judgment tasks contrasting the comparison of quantity with the comparison of proportions to determine whether the understanding of proportions develops before formal operations. Results indicated that the comprehension of abstract relations requires formal operations.…

Two studies demonstrated dissociation between preschoolers' understanding of pictorial and mental representations. Results showed that false picture tasks were significantly easier than false belief tasks. There was no correlation between performance on the two. Children were trained on false belief, false picture, or number conservation tasks;…