Teaching assistants' performance at identifying common introductory student difficulties revealed by the conceptual survey of electricity and magnetism

TL;DR

This study evaluates teaching assistants' ability to identify common student misconceptions in electricity and magnetism using the CSEM, revealing they often underestimate question difficulty and misjudge common incorrect answers.

Contribution

It provides insights into TAs' pedagogical content knowledge regarding student misconceptions in physics and highlights areas for improving TA training.

Findings

TAs struggled to accurately identify student misconceptions.

TAs underestimated the difficulty of CSEM questions.

TAs misjudged the prevalence of certain incorrect answers.

Abstract

We discuss research involving the Conceptual Survey of Electricity and Magnetism (CSEM) to evaluate one aspect of the pedagogical content knowledge of teaching assistants (TAs): the knowledge of introductory students' alternate conceptions in electricity and magnetism as revealed by the CSEM. For each item on the CSEM, the TAs were asked to (1) identify the most common incorrect answer choice of introductory physics students and (2) predict the percentage of introductory students who would answer the question correctly in a post-test. Then, we used the CSEM post-test data from approximately 400 introductory physics students (provided in the original paper describing the CSEM) to assess the extent to which the TAs were able to identify the alternate conceptions of introductory students related to electricity and magnetism. In addition, we conducted think-aloud interviews with TAs who had at least two semester of teaching experience in recitations to explore their reasoning about this task. We find that the TAs struggled to think about the difficulty of the questions from introductory students' perspective and they often underestimated the difficulty of the questions. Moreover, the TAs often expected certain incorrect answer choices to be common among introductory students when in fact those answer choices were not common.