Self-guided digital single-sessions interventions can bolster student confidence in the short-term: evidence from two large randomized controlled trials.

College science courses are increasingly transitioning from the traditional lecture format to an active learning format. Active learning have shown to improve learning outcomes and reduce failure rates. However, the interactive nature of active learning classes might lead to fear of negative evaluation among some students that prevent them from engaging in small groups, with the whole class or in conversing one-on-one with the instructor. In this paper, we report the results from two randomized controlled trials (N(study1)=903; N(study2)=817) evaluating two self-guided digital single-session interventions (SSIs) designed to bolster confidence to speak up in different contexts in an active learning class, Anx-SSI (study 1 and 2) and FNE-SSI (study 2) compared to an active control condition. In both studies, we observed that students randomized to the experimental conditions experienced an increase in confidence immediately after completing the intervention compared to the students in the control condition. Both the experimental interventions were acceptable to students. In study 1, the effects on confidence persisted at 1-week follow-up for speaking up in small groups, whole class, and total confidence as well as at 10-week follow-up for confidence in speaking up in whole class. In study 2, however, the gains in confidence did not last at 1-week or 10-week follow-up. Our studies show that brief SSIs (<30 min) can increase confidence among undergraduate students in different contexts within active learning classes. We discuss the lack of long-term effects in study 2 and potential ways to maintain immediate gains in the long-term in future studies.