Tweaking Instructional Practices Was Not the Answer: How Increasing the Interactivity of a Model-Centered Organic Chemistry Course Affected Student Outcomes

It is common for conversations about improving college chemistry learning to focus largely (or solely) on changing the way classes are taught. We advocate treating chemistry courses as more than a collection of teaching methods; what is taught and assessed are likely at least as important as how courses are taught. To demonstrate the utility of a nuanced approach for characterizing learning environments, we report a study on the impact of changing instructional practices in a large-enrollment organic chemistry course. Two types of enactment were compared: one in which lecture was the sole instructional practice used and one in which classes spent ∼33% of their time together engaging with lecture-embedded questions. Analyses of what was taught and assessed demonstrates that both types of course placed substantial emphasis, in-class and on assessments, on students using fundamental disciplinary ideas (e.g., energy, bonding) to predict, explain, and model phenomena. We found that integrating interactivity into large group meetings, while keeping assessments and pacing the same, had no substantive impact on student performance on instructor-authored assessments or the correctness of explanations elicited by researcher-authored instruments. Encouragingly, many students in both cohorts were supported in using core ideas to construct expert-like explanations and models for phenomena in high- and low-stakes assessments. However, both more- and less-interactive classes were similarly inequitable based on race and first-generation status, and to a lesser extent, binary gender. This suggests that, even in a model-centered organic chemistry course, addressing persistent inequities will require more fundamental changes than simply lecturing less.