Dynamic Visualizations of Multi-body Physics Problems and Scientific Reasoning Ability: A Threshold to Understanding

Abstract

Visualization is a common and important step in expert-like problem solving across multiple disciplines. Within the context of physics education, significant intervention is often required to develop visualization skills with novice problem solvers. In particular, dynamic multi-body problems require mental models that incorporate multiple objects time-varying in space, which may require significant development of spatial and/or other cognitive abilities. We have investigated student abilities in applying a dynamic visualization to solve a simple multi-body problem and that ability’s correlation with scientific reasoning (SR) cognitive ability as measured by Lawson’s Classroom Test of Scientific Reasoning (LCTSR). A broad population of students (N = 212) attending a regional comprehensive university in the USA were classified into four SR categories based on Piaget’s theory of cognitive development: (1) concrete operational, (2) early transitional, (3) late transitional, and (4) formal operational. A short problem was also administered that required students to construct a dynamic visualization to correctly answer. Specifically, the problem involved a situation where two trains leave opposite stations once per hour. The stations are 3 h apart. The task was to determine how many trains an observer on one of the trains would see during the 3-h trip between stations. Through analysis of expressed student reasoning, we have found that students answering with 3–4 trains typically have built a visualization based on at least one set of trains remaining stationary. Students answering 6–7 trains typically recognize the evolving nature of the problem and construct an appropriate dynamic visualization with both sets of trains in motion. Students struggle to deploy a successful dynamic visualization when classified below formal operational level. Formal operational reasoners within the population succeed almost universally in applying a successful dynamic visualization. This suggests an epistemological threshold may exist, whereby students struggle with constructing dynamic visualizations before reaching a high-formal level of reasoning ability. This has implications for instruction and textbook/classroom problem construction, especially considering that a significant majority of students enrolled in introductory physics courses within our population demonstrate late transitional and below SR levels.