Benefits of turning the illustrations in a narrated slideshow into cartoons: An extension of the positivity principle

What is the effect on students' learning of converting a narrated slideshow with simple line drawings (original group) into one in which the key elements are rendered as colorful cartoon-like characters (cartoon group)? We conducted two between-subjects experiments in which the narrator's voice in both groups was a computer-generated female happy voice in Experiment 1 or a real female happy voice in Experiment 2. The cartoon group scored higher on a transfer posttest than the original group in both experiments. On subsequent questionnaires, the cartoon group reported feeling more positive (i.e., happy and content) during learning than the original group (in Experiment 1 and the combined experiments); and reported that the instructor was more engaging, better at facilitating learning, and more human-like (in Experiment 2 and the combined experiments). The results are consistent with the positivity principle, which predicts better learning from lessons in which key elements induce positive emotions.