Examined whether the density of play continues to increase as children grow older. Four- and five-year-olds made simple constructions using few materials, six- and seven-year-olds made more constructions with more materials, and eight-to ten-year-olds made fewer but much more extensive and integrated constructions. (Author/DB)

Research on object exploration by infants addresses milestones in the process by normally developing infants, including spontaneous manipulation strategies. Implications for developmentalists working with high-risk preterm infants are noted, including the need for direct assistance in manipulation and for selection of materials. (CL)