The Complexity of Visual Learning Materials Moderates the Effects of Instructors' Facial Expressions in Instructional Videos

ABSTRACT Background Research shows that instructors' happy facial expressions can evoke students' positive emotions and enhance their learning motivation. Nevertheless, debate persists in the literature regarding the impact of instructors' happy facial expressions on students' learning performance. This may be attributed to the potential social benefits of instructors' happy facial expressions being counterbalanced by the concurrent attentional costs. Objectives This study examined whether the visual complexity of learning materials (simple vs. complex) moderated the effect of instructors' facial expressions (happy vs. bored) on students' learning performance. Methods Participants ( n = 58) watched two instructional videos featuring an instructor displaying either happy or bored facial expressions while presenting either complex or simple visual materials. Result and Conclusions The experimental results revealed that, when simple visual learning materials were used, the instructor's happy facial expressions significantly improved students' learning performance. In contrast, when complex visual learning materials were used, differences in the instructor's facial expressions did not significantly affect students' learning performance. Implications Our findings suggest that instructors should consider both the complexity of the visual learning materials and their facial expressions when teaching English vocabulary as a foreign language through instructional videos, particularly when teaching female students. Specifically, when using simple visual learning materials, instructors should display happy facial expressions to enhance student performance. Conversely, when using complex visual learning materials, instructors should avoid overly expressive facial expressions that may distract students from the learning content.