The Principal Investigators will conduct an R and D project that will translate past laboratory studies into practically relevant instruction. Their goals are: (1) to develop theoretically based, but practically useful methods and materials for teaching effective problem solving in the prototype domain of basic physics; (2) to increase understanding of the cognitive processes needed to learn such problem solving; and (3) thus to develop research-based guidelines for designing problem-solving instruction in other quantitative sciences. The effort will use interactive instructional methods to teach explicitly a general problem-solving strategy, a well-organized knowledge base, and the decision and checking processes needed to apply the strategy. The instructional methods, materials, and underlying theoretical models will be cumulatively improved by a sequence of instructional experiments, extending from small-scale studies to classroom contexts. In these the students will be observed in detail, the data analyzed (partially by computer modeling) to elucidate underlying learning difficulties, and the results systematically used to revise the instructional approach. Prototype instructional materials will be produced and made available to teachers and other researchers.