Teaching microbial physiology can be challenging because it is easy to overwhelm students with information. Microorganisms metabolize a number of compounds as carbon and/or energy sources and use diverse pathways and modes of energy conservation. In addition, an enormous amount of information has accumulated on microbial metabolism. However, such information is critically needed if the students are to understand how microorganisms function.What are the ways in which instructors can respond to this challenge? The traditional approach of teaching microbial physiology as a lecture course is efficient in that it allows the teacher to present a large amount of information to many students. The downside of this approach is that it fosters passive learning where students expect to be told what to learn and how to learn it (31). Students do not develop the skills or the interest to learn on their own, and enthusiasm for the course is low. It is also counterproductive, given what we know about how students learn and what the mission of a university is. It is clear that learning styles of students in science classes are diverse (5,6,12,22). Thus, at best, the lecture format reaches only a select group of students. The mission of a university should be to introduce students to research and inspire in them the passion for discovery (16). Finally, there is the temptation to cover as much material as possible in a lecture, but this often comes at the expense of in-depth understanding of key concepts such that students have difficulty applying these concepts in new contexts (1). These points raise the question of how we can change our mode of instruction so that students acquire the information base they need, but they also engage in the genuine inquiry that is at the heart of the scientific process.A number of studies indicate that active learning, especially the use of small group activities, improves student performance and enthusiasm in diverse college courses (2-7, 9, 18, 19, 21, 31, 37). Several recent papers examine the value of small groups for teaching microbiology. Suchman et al. (31) found that small group activities were effective in an introductory microbiology course if the activities had welldefined and obtainable goals and clearly articulated guidelines. Cooperative learning activities increased student interest in research in microbiology (5) and the inclusion of collaborative learning and other activities improved the final grades of students in an introductory microbiology course for allied health students (19). Trempy et al. (32) found that cooperative learning where students work interdependently on well-defined tasks resulted in high retention of key concepts and high student satisfaction in a microbiology course that included both science, mathematics, engineering, and technology (SMET) majors and non-SMET majors.These reports on the use of small groups indicate some clear benefits from small groups in comparison with a primary reliance on lecturing. However, there may be additional benefits in a mor...