Fluctuations in Student Understanding of Newton's 3rd Law

TL;DR

This study tracks student understanding of Newton's Third Law over an academic year, revealing fluctuations influenced by instructional focus and demonstrating the importance of teaching context on student learning.

Contribution

It provides detailed response curves showing subtle learning dynamics and effects of instructional shifts on student understanding of physics concepts.

Findings

Positive effect of direct instruction on understanding

Dips in correct responses linked to topic changes

Rebound in understanding after returning to vector-based topics

Abstract

We present data from a between-student study on student response to questions on Newton's Third Law given throughout the academic year. The study, conducted at Rochester Institute of Technology, involved students from the first and third of a three-quarter sequence. Construction of a response curve reveals subtle dynamics in student learning not captured by simple pre/post testing. We find a a significant positive effect from direct instruction, peaking at the end of instruction on forces, that diminishes by the end of the quarter. Two quarters later, in physics III, a significant dip in correct response occurs when instruction changes from the vector quantities of electric forces and fields to the scalar quantity of electric potential. Student response rebounds to its initial values, however, once instruction returns to the vector-based topics involving magnetic fields.