A fine-grained teaching activity to establish conceptual coherence in introductory physics concepts and representations

The sequence of representations used to introduce new knowledge and the context in which this is done is critical to both effectively build on prior knowledge and establish conceptual coherence in physics. Ongoing reports indicate that current teaching activities fail address student difficulties to obtain conceptual understanding and-coherence between relevant physics representations and concepts. There is a need for fine-grained topic specific multiple representational teaching activities to enhance coherence in physics knowledge. In this paper we present a teaching activity for undergraduate physics, built on using motion diagrams to specifically relate the concepts and representations in kinematics, in particular for the concept of free fall. The teaching activity follows a conceptual qualitative approach to teaching kinematics concepts and is informed by the results of a broader Design Based Research study. In the teaching activity the concept of acceleration is introduced qualitatively as the net force to mass ratio followed by drawing motion diagrams to visualize the motion of the objects in free fall. The motion diagrams are implemented to support conceptual qualitative interpretation of mathematical representations such as graphs and equations, to enhance transfer of knowledge between representations and coherence between relevant concepts and representations. The contribution of this research lies in presenting an argument for a conceptual qualitative approach to teaching introductory mechanics and introducing a teaching activity based on the value offered of including motion diagrams in the teaching activity to enhance coherence between physics representations and between physics concepts.