Compares current science education reform efforts with those of the 1960s to enhance student learning. Discusses how an "alternative models" view of scientific explanation can contribute to reforms of course goals, social aspects of science learning, instructional practices, and roles for technology. Contains 50 references. (ZWH)

Research on the development of ability to control variables during adolescence is reviewed. The first section discusses studies by Piaget and his collaborators, replications of Piaget's studies, and related studies by other investigators. Factors which influence performance on controlling variables tasks are delineated; the existence of Piaget's…