In his 1979 "Human Development" article reprinted in this anniversary issue, James Wertsch presented an approach to genetic analysis of the shifting regulation of problem-solving behavior in early childhood. In my reflections on Wertsch's seminal contribution, I discuss ways that subsequent inquiry built upon ideas he elaborated in the…

Pragmatic and semantic problem solving are examined as processes that enhance acquisition of mathematical knowledge. It is suggested that development of mathematical cognition involves restructuring and that math teachers can help restructure children's knowledge systems by providing them with situations in which semantic and pragmatic problem…

Proposes causal field theory as a model of causal reasoning. Suggests that anomaly detection through comparison with natural events triggers causal reasoning. This anomaly is interpreted in terms of agency; therefore, natural phenomena can be understood through an appeal to agency. The mechanism proposed never changes with development, whereas…

Proposes analogy as the central mechanism of knowledge acquisition in formal domains. Discusses experimental data on preschoolers' knowledge of one-to-one correspondence and college students' understanding of force decomposition. Suggests that a knowledge base domain is a thematically organized knowledge structure and that thematic relations in a…