BackgroundLearning with explainer videos can foster learning. However, their effects on subsequent learning are still unclear. On the one hand, they might increase situational interest and scaffold subsequent learning. On the other hand, they might hinder subsequent learning by fostering an illusion of understanding. In case of the latter, the question arises of whether providing prompt-questions after an explainer video would prevent an illusion of understanding. Therefore, we investigated the effects of medium and prompt-questions on subsequent learning with text. SampleOne hundred thirty-three teacher students and psychology students from a German university. MethodsIn an online study with a 2x2 between-subjects design, we investigated the effects of medium (video vs. video-script) in learning phase 1 and prompt-questions (yes vs. no) on subsequent learning with text. ResultsAs expected, watching the video made the content seem more interesting and less difficult. Contrary to the illusion-of-understanding-assumption, this did not result in learners overestimating but rather underestimating themselves. Moreover, while prompt-questions in the video condition fostered learning, they impaired learning in the video-script condition. Exploratory mediation analyses revealed that in the prompt condition, the superiority of the video was mainly driven by the quality of the prompt-answers rather than the time learners invested in answering the prompt-questions. ConclusionsOur findings suggest that explainer videos combined with prompt-questions can foster learning with subsequent text. However, further research is necessary to replicate the findings under more controlled conditions and to investigate the underlying processes in greater depth.