Studies in the role of play in child development are classified in terms of their major correlates or dependent variables: (1) creativity, (2) problem solving, (3) language development, (4) logical skills, and (5) social knowledge. Study designs are critically examined, and internal and external validity problems are noted. (Author/PN)

Developmental assumptions that are frequently regarded as constraints on elementary school science curricula are analyzed. The argument that elementary school children cannot function as experimentalists because they have not yet attained formal operational thought is not supported by the Piagetian or non-Piagetian research reviewed. (SLD)