Teaching and assessing reasoning and deductive logic in an introductory physics course

Like many physics professors, we have noticed that our students seem to struggle to answer specific conceptual questions. They are distracted by surface-level features of a problem which are not relevant to the solution, their answers change significantly with slight changes to the wording or presentation of a question and, most worryingly, they are capable of verbalizing correct conceptual knowledge only to immediately give answers which contradict that knowledge. Our explanation for this observation was that our students struggled with reasoning; their difficulty lay not in lacking the physics knowledge necessary but the ability to use that knowledge productively. To address this we redesigned our course in the Spring 2025 semester to emphasize reasoning and deductive logic when answering physics questions. We also redesigned our exams to help us determine the extent to which student struggles could be attributed to lack of content knowledge or difficulty reasoning. Here we will discuss what reasoning skills we taught and how we integrated them into our curriculum. We will also discuss the implementation and design of these new exams and demonstrate how we analyzed the results to better understand our students.