Abstract
BACKGROUND: The classical "lever balance problem" has always been a challenge for students, as it requires special coordination of weight and distance changes. At the core of this coordination lies the "third" magnitude of the multiplicative structure, the torque, which is often overlooked in psychological research on the development of the equilibrium concept. OBJECTIVE: An introductory computer-supported module was developed based on the principles of developmental instruction (Davydov). Our research goal was to demonstrate one of the delayed effects of the preliminary multiplicative concept formation in the fifth grade on students' acquiring the corresponding topic in elementary physics in the seventh grade. DESIGN: The experimental group included 43 seventh-graders who had been taught using our introductory equilibrium curriculum two years prior (4 lessons). The control group (44 seventh-graders) from the same schools had not participated in any special curriculum. The assessment procedure simulated the "physics lesson" with reading the textbook and watching the educational video. Then students had to complete five balance tasks of two types (with one or multiple locations for weights on each lever arm). RESULTS: The results revealed that students in the experimental group did significantly better solving the "scattered weights" problems. When the digital simulation allowed all students to resort to trials, the control group relied on the "trial and error" method signiicantly more than the experimental group. CONCLUSION: Students' adherence to the "conceptual" approach was most clearly revealed through their way of solving "scattered weights" tasks and the number of "excessive" trials in computer simulation. The results proved the lasting effect of our introductory curriculum.