highly significantp < 0.001
5 Discussion 5.1 The effect of acceleration on cognitive load From the results of the main effects test, the increase in cognitive load by accelerated playback of instructional videos reached a highly significant level (g = 0.59, p < 0.001), and the hypothesis H1 was valid, i.e., accelerated playback significantly increased the cognitive load of learners compared to original speed playback.