A tale of two sections: An experiment to compare the effectiveness of a hybrid versus a traditional lecture format in introductory microbiology

Two sections of an introductory microbiology course were taught by one instructor. One was taught through a hybrid format and the other through a traditional format. Students were randomly assigned to the two sections. Both sections were provided with identical lecture materials, in-class worksheets, in-class assessments, and extra credit opportunities; the main difference was in the way the lecture material was delivered—online for the hybrid section and in person for the traditional section. Analysis of final grades revealed that students in the traditional section did significantly better than those in the hybrid section (p < 0.001). There was a significant main effect of class standing (p < 0.01). When performance in the two sections was compared for each class year separately, the differences were only significant for sophomores (p < 0.001); freshmen, juniors, and seniors did not perform differently in the hybrid versus the traditional section. An anonymous midterm survey suggested factors likely contributing to the overall lower success of students in the hybrid section: some students in the hybrid section did not take lecture notes and/or use the audio component of the online lectures, suggesting minimal interaction with the lecture material for these students.