Investigating the effects of beat and deictic gestures of a lecturer in educational videos

Lecturers in educational videos often use gestures to emphasize what has been said or highlight learning relevant information, which is visible on the screen. However, differences in types of lecturer gestures, such as rhythmic (beat) gestures and signaling (deictic) gestures, have not been investigated thoroughly yet concerning human lecturers in educational videos. In two experiments (N1 = 108; N2 = 121), participants received an educational video about weather phenomena (Experiment 1) or the industrial revolution (Experiment 2). Videos were manipulated in terms of the type of lecturer's gestures in the video (beat gestures vs. deictic gestures vs. no gestures). Learning outcomes, mental load and effort, parasocial interaction, social presence, affective rating, and agent-persona perception (Experiment 2) were measured. Results indicated a significant effect of gestures on retention performance in both experiments. In line with the signaling principle, deictic gestures enhanced learning outcomes. In contrast, beat gestures did not foster learning in comparison with a video without gestures. These results are interpreted considering lower mental load, higher social presence, and parasocial interaction in the signaling condition. In particular, attention towards the lecturer was significantly enhanced in the condition with deictic gestures in both experiments.