Comparing Online and In-Person Learning Outcomes with Synchronous Hybrid Instruction: A Natural Experiment During COVID-19

Abstract Synchronous hybrid learning is a teaching approach designed to connect online and in-person students during real-time course sessions. Despite its growing adoption, there are gaps in understanding how course delivery modality impacts undergraduate learning outcomes. This study leveraged a biology undergraduate course in Fall 2021, which served as a natural experiment due to COVID-19 distancing measures. Students participated in either online or in-person sections within a synchronous hybrid framework. Using multivariate regression and mediation analysis, we explored how modality influenced student exam performance, considering demographics and engagement with course materials. The results indicated no significant direct effect of modality on exam outcomes. However, student engagement during synchronous sessions was a key factor enabling online students to achieve comparable performance to their in-person peers. A follow-up analysis in Fall 2022, when students were fully separated by modality, similarly found no direct impact of modality on exam performance. Unlike the previous semester, engagement did not mediate the relationship between modality and outcomes. These findings suggest that active participation during synchronous hybrid sessions is critical for bridging the gap between online and in-person learning experiences.