The Sandwich principle: assessing the didactic effect in lectures on “cleft lips and palates”

BACKGROUND: A teaching concept, that takes individual learning and personal belongings into account, is called the “sandwich principle.” This didactic method is an educational concept that alternates consecutively between individual and collective learning phases during a course. This study aimed to prove whether the application of the sandwich principle in lectures increases the learning outcome compared with classical lectures. METHODS: All participants (n = 64) were randomly allocated into two groups. One group attended a classical face-to-face lecture and the other attended a lecture that was modified according to the sandwich principle, including activating elements. To compare knowledge gain after the lectures, all the participants had to answer a test comprising40 single-choice questions. In addition, the lectures were evaluated. RESULTS: Students attending the sandwich lecture had significantly better scores in the test than those who attending the classical lecture (p < 0.001). The mean test score of the sandwich group was 63.9% [standard deviation (SD) = 10] points and of the control group 50.2% (SD = 13.7 points). Overall, both the class conditions showed good evaluation results; however, students of the sandwich lecture were more satisfied with the lecture format compared with the other group. CONCLUSION: Our study results confirm the thesis that the application of the sandwich principle in lectures increases the learning outcome compared with classical lectures. Even with a big audience, the sandwich design presents a concept that helps maintain high attention levels and addresses individual learning styles.