Representational differences in how students compare measurements

TL;DR

This study introduces the SPRUCE assessment tool to evaluate how students understand measurement uncertainty, revealing differences in reasoning based on numerical versus pictorial representations, which can inform instructional strategies.

Contribution

The paper presents a novel assessment tool, SPRUCE, that uncovers representational differences in student reasoning about measurement uncertainty in physics experiments.

Findings

Students perform better on pictorial questions than numerical ones.

Students rely on different reasoning modes depending on the representation.

Instruction can be improved by leveraging students' strengths in pictorial reasoning.

Abstract

Measurement uncertainty plays a critical role in the process of experimental physics. It is useful to be able to assess student proficiency around the topic to iteratively improve instruction and student learning. For the topic of measurement uncertainty, we developed an assessment tool called the Survey of Physics Reasoning on Uncertainty Concepts in Experiments (SPRUCE), which aims to assess students' knowledge, and use of, a variety of concepts related to measurement uncertainty. This assessment includes two isomorphic questions focused on comparing two measurements with uncertainty. One is presented numerically and the other pictorially. Despite the questions probing identical concepts, students answer them in different ways, indicating that they rely on distinct modes of representation to make sense of measurement uncertainty and comparisons. Specifically, students score much higher on the pictorially represented item, which suggests possible instructional changes to leverage students' use of representations while working with concepts of measurement uncertainty.