Argues that reasoning is not governed by mental logic or models. Proposes new operational semantic theory, in which reasoning is based on children's operational understanding of key terms in a given problem. Reports results of a study of class inclusion in which dramatic differences in performance were found as the result of linguistic context.…

Five articles explore various theoretical aspects of problems and problem solving skills. Highlights include strategies to learn problem solving skills; knowledge structures; metacognition; behavioral processes and cognitive psychology; erotetic logic; creativity as an aspect of computer problem solving; and programing as a problem-solving…