Individual and group reflection in lecture-based large groups lead to comparable learning success.

Objective: The study aims to elucidate a possible effect of individual reflection (IR) or group reflection (GR) on short-term and long-term memory retention in a large group lecture-based environment.

Methods: In this quasi-experimental study 656 medical students were enrolled to compare the impact of IR and GR directly after the lectures and 2 months later. Students were divided into two groups and given two different lectures using IR or GR in a cross-over fashion. Memory retention was estimated using multiple-choice questions analyzed by Student's T‑test.

Results: Memory retention was similar using both reflection methods at baseline (p = 0.867; p = 0.971) and follow-up (p = 0.885; p = 0.945). Interestingly, both reflection methods fostered good memory retention over time. Students' self-assessment initially favored GR as more beneficial, an effect that faded over time.

Conclusion: Reflection might be a promising tool to foster memory retention in large lecture cohorts without added benefit from social interaction.