Investigates the effects of two context variables on the performance of seventh-grade students on a qualitative and numerical proportional reasoning test. Explores the nature of the relationships between rational number skills, qualitative reasoning about ratios, and numerical proportional reasoning. (Author/YP)

Describes the problem-solving behaviors of experts and novices engaged in solving seven chemical equilibrium problems. Lists 27 behavioral tendencies of successful and unsuccessful problem solvers. Discusses several implications for a problem solving theory, think-aloud techniques, adequacy of the chemistry domain, and chemistry instruction.…

Examined were the relationships between three qualities: students' knowledge of chemical terms, the relationships they recognize between these terms, and their achievement. Used were an explanation test, an achievement test, and a connectivity test. Results indicated knowledge of terms was a necessary, but not sufficient, prerequisite for…

Describes an exercise designed for an introductory level calculus-based physics class. Presents a problem on why a rod dipped in water is stable when it is oriented at an angle with the vertical. Discusses qualitative understanding, mechanical understanding using equations, and experimental verification of the problem. (YP)

Describes the selection and implementation of an authentic assessment model for evaluating students' science laboratory knowledge and skills. Provides sample problems and a scoring form for the performance-based science laboratory test. (MDH)