In-lecture quizzes improve online learning for university and community college students.

Online classes are now integral to higher education, particularly for students at two-year community colleges, who are profoundly underrepresented in experimental research. Here, we provided a rigorous test of using interpolated retrieval practice to enhance learning from an online lecture for both university and community college students (N = 703). We manipulated interpolated activity (participants saw review slides or answered short quiz questions) and onscreen distractions (control, memes, TikTok). Our results showed that interpolated retrieval enhanced online learning for both student groups, but this benefit was moderated by onscreen distractions. Surprisingly, the presence of TikTok videos produced an ironic effect of distraction-it enhanced learning for students in the interpolated review condition, allowing them to perform similarly to students who took the interpolated quizzes. Moreover, we showed in an exploratory analysis that the intervention-induced learning improvements were mediated by a composite measure of engaged learning, thus providing a mechanistic account of our findings. Finally, our data provided preliminary evidence that interpolated retrieval practice might reduce the achievement gap for Black students.