Preparing learners to self-explain video examples: Text or video introduction?

The use of video examples in (online) learning scenarios is rapidly growing and can be very effective for learners with little or no prior knowledge. Previous research identified so-called self-explanation prompts as the method of choice to make learners deeply process the examples' principles. From a cognitive load perspective, it seems feasible to prepare learners for such self-explaining via written explanations and an introductory example-leaving the optimal presentation mode of this introductory example in question. We thus aimed to analyze effectiveness and efficiency of the presentation mode (i.e., written vs. video-based) of the introductory example. In our experiment, students (N = 42) received a written explanation supplemented with an introductory example, before they self-explained video-based examples. We found similar learning processes (i.e., cognitive load and self-explanation quality) and a large effect on learning outcomes (i.e., conceptual knowledge about the examples' principles)-irrespective of the introductory example's presentation mode. However, the written introductory example revealed efficiency advantages over the video-based one: studying it required less time, and recalling its principles required less mental effort. Finally, we identified previous experience with video-based learning as a predictor for learning outcomes.