How much do Different Factors of Elementarization Matter? Comparing Two Dynamical Approaches to Newton’s Second Law

Abstract Newtonian mechanics is challenging to teach and learn. Even after instruction, students do not have an adequate understanding. To address this problem, several approaches to teaching Newtonian mechanics have been developed, but differences in several variables make it unclear which changes lead to the positive results. Furthermore, traditional instruction is often chosen as the reference group, remaining unclear what is understood by ‘traditional’. This study uses a standardized comparison group in the form of a one-dimensional adaptation of the two-dimensional dynamic mechanics concept to investigate the effect of certain factors of elementarization (1D vs. 2D, constant force vs. force impacts, use vs. avoidance of acceleration) on students' learning progress in early secondary school, controlling all other influencing factors. Conducted during the school years 2019/20 and 2020/21, 23 teachers in 46 classes taught 819 students (grade 8 and 9) using two different mechanics concepts. In both treatment groups, a highly significant learning progress in the range of a teacher effect could be demonstrated. Comparing the learning progress between the treatment groups there is no difference. So, a dynamic approach works, and the choice of factors of elementarization above is potentially not crucial for the quality of instruction.