The ability of 5-month-old infants to recognize two-dimensional (pictorial) representations of three-dimensional objects was investigated. Subjects were 24 5-month-old infants. The novelty preference technique was employed: all infants were familiarized with a three-dimensional object--a doll. Following familiarization, three novelty tests were…

Three experiments concerned with methods of teaching mathematical concepts to 2- and 3-year-olds were carried out. The first experiment, in which 12 children were taught the concepts "fat" and "skinny," showed that (1) explicit verbal representation of the concepts was a more effective instructional technique than formulation in terms of an…