Continuous Feedback at Scale: Closing the Instruction–Response–Feedback Loop in a Large Physical Chemistry Laboratory Course

Abstract

Abstract The classical structure of physical chemistry laboratory courses often relies on delayed, report-based assessment, which can hinder conceptual understanding and student engagement, particularly in large classes. In this study, we report the redesign of an undergraduate physical chemistry laboratory course aimed at closing the Instruction–Response–Feedback (I–R–F) loop through systematic implementation of continuous and structured feedback mechanisms. The course was offered to two cohorts of approximately 50 students each, one during the daytime and one during the evening, allowing assessment of both feasibility and robustness across different class contexts. Key elements included short postlaboratory assessments completed during the laboratory session, weekly collective discussion sessions, and guided laboratory reports structured as process-oriented guides. Pre- and postcourse self-assessment surveys were administered to both cohorts. Statistically significant improvements were observed in the majority of items surveyed for both cohorts. The proportion of confident responses increased from 46% to 81% in the daytime cohort and from 36% to 76% in the evening cohort, with both converging to comparable levels by the end of the course. These results demonstrate that scalable closure of the I–R–F loop is feasible in large laboratory classes and is associated with increased student engagement and perceived learning in experimental physical chemistry courses.