Contends that emergent developmental sequences are energized in a continuous interaction with environmental influences. Asserts that a developmentally and individually appropriate curriculum is sequential and matched to the naturally emerging developmental sequences of the child. Proposes four research emphases for the 1990s. (CFR)

Maintains that a major theme in Lev Vygotsky's later research was concept formation or conceptual development in child development. States that Vygotsky argued that the acquisition of mature academic concepts forms the crowning achievement of adolescence. Argues that the view raises a number of criticisms. (CFR)