Abolaji Akinyemi · PERC Summer Meeting 2020
A tale of two approaches: Comparison of evaluation strategies in physics problem solving between first- and third-year students.
One expected student outcome of physics instruction is a set of quantitative reasoning skills that includes evaluation of problem solutions. As part of a larger project, we developed and administered tasks to physics students that probe their use of these kinds of evaluation strategies. In an interview setting, we asked pairs of students either first-years or juniors, to evaluate expressions for the final velocities of two skaters involved in a one-dimensional elastic collision. The techniques used by both groups show the differences between novice and intermediate versions of certain evaluation strategies. We focus on the role of algebra and mathematical operations in the checking process as well as how the students seem to view equations. For instance, first-years strategies focused on numerical substitution to satisfy conservation of momentum, while juniors checked special cases of mass and/or velocity and used ratios of variables rather than specific numerical values.