Learning science and the illusion of understanding: exploring the effects of integrating learning tasks after explainer videos

Explainer videos are increasingly used to support science learning. While prior research has demonstrated their potential, studies have also identified limitations - particularly their tendency to foster an illusion of understanding, where learners overestimate their grasp of a topic despite gaps in their actual knowledge. Pairing explainer videos with cognitively engaging elements may help mitigate this effect. This paper reports two experimental studies examining the immediate and long-term effects of learning tasks following a physics explainer video on learners' illusion of understanding. Study 1 (N = 244 learners) compared high-level learning tasks with watching the video alone. Study 2 (N = 175) compared high-level and low-level tasks. Results show that high-level learning tasks significantly reduce the illusion of understanding immediately after the intervention compared to watching the video alone (t(88) = 6.50, p < .001, d = 0.69). Over the long term, both high-and low-level tasks are similarly effective. Learners with lower prior content knowledge are more susceptible to an illusion of understanding. We conclude that explainer videos should not be used in isolation in science classrooms. To prevent misjudged understanding - particularly among students with limited prior knowledge - they should be combined with cognitively demanding follow-up activities.