Suggests some difficulties and challenges in understanding and teaching Piaget's new theory. Outlines some differences between Piaget's new and standard theories, such as the diminished status of the emergent skills that mark the onset of concrete operational thinking and the perception of achievements in concrete operations as empirical…

A broad literature review revealed that younger children are more likely to categorize objects along complimentary dimensions than older children who tend to categorize according to similarity. This developmental change is discussed in terms of etiology--internal organismic changes or environmental changes. (DP)

A precise formulation of both cognitive structure and its related theory is provided through use of the mathematical theory of categories. Weaknesses and imprecision in cognitive theory are identified. Using category theory, cognitive structure and related Piagetian theoretic terms are precisely defined and some interrelationships are discussed.…

Results of this investigation support the view that operating class inclusion requires coordination between logical intension and extension, a process which can be facilitated through training. (Author/WY)

Comments on Moshman's discussion, in this issue, of reasoning as self-constrained thinking, arguing that differences in type of reasoning constraint probably reflect different knowledge bases but do not necessarily imply different processes. The fact that different tasks require different kinds of knowledge does not mean that different processes…

Proposes a theory of reasoning and outlines four general types of reasoning (case-based, law-based, coherence-based, and dialectical) based on the constraints the reasoning seeks to honor. The development of reasoning is presented as a continuing construction and reconstruction of self-constraints and justifications for those constraints,…

Outlines Piaget's late ideas on categories and morphisms and the impact of these ideas on the comprehension of the inclusion relationship and the solution of arithmetic problems. Reports a study in which fourth through sixth graders were given arithmetic problems involving two known quantities associated with changes rather than states. Identified…

Examination of the way in which children conceive the development of animals shows that there are parallels among concepts of development with those of the periods of concrete operations and formal operations. The conception of development seems to advance further in the subsequent period of dialectical thought. (MS)