Piaget's enduring contribution to developmental psychology.

Piaget's transformation of society's conception of childhood thought and intelligent is described in 4 periods in the history of his research program, which spanned from the 1920s to the 1980s. The account stresses the enduring contribution to developmental psychology of Piaget's constructivism, his description of developmental mechanisms, his cognitivism, his explication of structural and functional analysis, and his address of epistemological issues and nontraditional methodologies