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)

Describes and discusses the rule-assessment approach, a new research strategy for studying developmental sequences in children's acquisition of knowledge. Four experiments were conducted to illustrate the utility of this approach across a variety of concepts and a wide range of ages (three-year-olds to college students). (Author/CM)

Two experiments which investigated the young child's ability to deal with multiplicative classes and relations (considered behavioral indices of concrete operations thought) in double series and cross class matrices are described and discussed. In the initial study, 160 children from preschool through grade 2 received six matrix subtasks…

Piaget, in describing the sequence of classificatory development, describes class inclusion as composed of two processes; hierarchical classification and post-whole comparisons. In the experiment reported here, elementary school children, trained in the concept of sets in first grade mathematics were given a task where they were required to assess…

Kindergarten, second-grade, fifth-grade, and college subjects were tested in a serial-position recall task under each of four conditions: Visual stimuli/visual recall cue, visual stimuli/auditory recall cue, auditory stimuli/visual recall cue, auditory stimuli/auditory recall cue. Visual stimuli were pictures of common animals and objects;…