High school students’ conceptual change navigation about buoyant force when using Model-centered Instructional Sequence (MIS)

Abstract

This study examined how students’ concepts of buoyant force change through a Model-centered Instructional Sequence and analyzed the factors that lead to the development of unscientific concepts. Sixteen high school students took an after school class entitled, ‘Understanding Concepts of Physics using Model-centered Instructional Sequence’. Seven focused students were interviewed, and their initial and revised models in a problematic situation where stopped objects with controlled mass and volume remained at rest in different depths of water were analyzed. The results were as follows: First, they usually explained the movement of objects in water by using the concept of density. Second, even though they knew that the sum of the force of gravity and the buoyant force on an object at rest in water was zero, they had the unscientific idea that a decreased buoyant force caused the object to stay at a lower position in the water because they mistook the buoyant force and the hydraulic pressure for two physical quantities in the same dimension when trying to find the answer by adding hydraulic pressure to buoyant force or subtracting hydraulic pressure from buoyant force. © 2017, The Korean Physical Society. All rights reserved.