Contrasts recent views of learning and cognition with cognitive learning theories of the late 1950s and early 1960s. Maintains that Jerome Bruner's spiral curriculum approach, still valuable, is not sufficient to explain cognitive development. Proposes a lattice-like cognitive development structure, inviting differing paths of exploration. (CFR)

Reports on the assessment of student thinking in the area of commitment to the laws of conservation of matter and energy during a study of conceptual change among introductory chemistry students. States four conditions upon which strategies for conceptual change are based. (RT)