Teaching Methods to Promote the Application of The Rule of Composition and Decomposition of Force in Junior High School Science Lessons.

Abstract

The purpose of this article was to examine the effectiveness of a lesson plan to promote the application of the rule of composition and decomposition of force in science lessons at a junior high school. The lesson plan aimed to (1) incorporate the operational rules and “converse-type questions”, and (2) clarify the differences and similarities between composition rules and decomposition rules by using super-ordinate rules. The effectiveness of the lesson plan was evaluated based on post-evaluation tasks and lesson process. The analysis of 83 third graders in junior high school showed that, with the exception of certain problems, in the post-evaluation tasks the rate of correct responses was around 50%. Moreover, the incorrect responses indicated a confusion between the composition rule and the decomposition rule. The analysis of the teaching-learning process showed that these results would had been caused by “converse-type questions” and the lack of teacher’s explanation of hierarchical relationships between the super and sub-ordinate rules, as well as the lack of teacher questions concerning the overall consequences of the rule statements.