Argues that the question of whether information representation and processing are domain-general or domain-specific is neither meaningful nor answerable. Researchers should be asking questions about ways in which representation and processing are domain-general and ways in which they are domain-specific. (RH)

This article offers four models of what may be going wrong in the transmission of thinking skills from textbooks and teachers to students. Sources of the problem are identified and possible solutions, alternatives, and strategies of "teaching for thinking" are described. (JL)

The unified theory described in this paper characterizes human reasoning as an information processing system with a hierarchical sequence of components and subtheories that account for performance on successively narrower tasks. Both deductive and inductive theories are subsumed in the unified componential theory, including transitive chain theory…