Physiology, particularly metabolic physiology, covers the fundamentals of biophysics and biochemistry for nutrient absorption, transport, and metabolism. Engaging pre-health students in experimentation may facilitate students’ learning and their in-depth understanding of the mechanisms coordinating homeostatic control. In addition, it may promote critical thinking and problem-solving ability if students are engaged in active learning.

Traditionally, students are provided instructions that detail the stepwise procedures before an experiment or demonstration. Although students are encouraged to ask questions before and during the experiments, an in-depth discussion would not be possible until they understand each step and the underlying principles. This is particularly true nowadays when commercial kits come with stepwise instructions where no explanation can be found of principles behind the procedure. The outcomes may contrast in three ways: (1) students are happy with the perfect data they acquire by following the instructions provided by the manufacturer, but they miss the opportunity to chew on the key principles that are critical for students to develop creative thinking; (2) students are frustrated as they follow the instruction but fail the experiments, without knowing what is wrong and where to start for trouble shooting; and (3) driven by self-motivation, students dig into the details and interact intensively with the instructor to grasp the principles of the procedure. As such, the students can produce reliable data and interpret the procedure and data with confidence, and in addition, they may effectively diagnose operational errors for trouble shooting. Evidently, the 3^rd scenario demonstrates an example of active learning, which is desirable but not common in a traditional model of experimentation.

To engage students in active learning, one of the strategies is to remove the ready-to-go procedure from the curricular setting but request the students to submit a working protocol of their own version at the end of an experiment. Instead of a stepwise procedure (i.e., a “recipe”), the students are provided with reading materials that discuss the key principles of the analytical procedures. When students show the competency in the understanding of the principles in a formative assessment (e.g., a 30-min quiz), they are ready to observe the demonstrations step by step, taking notes and asking questions. Based on their notes and inspiration from discussion, each student is requested to develop a protocol of their own version. Depending on how detail-oriented the protocols are, the instructor may approve it or ask students to recall the details and revise their protocols before moving forward. Once students show competency in the protocol development, they are ready to conduct the steps in groups under the instructor’s (or teaching assistant, TA’s) supervision. Assessment on precision and accuracy is the key to examine the competency of students’ operation, which also provides opportunities for students to go back to improve or update their protocols. In the case of unexpected results, the students are encouraged to interpret and justify their results in a physiological setting (e.g., fasting vs. feeding states) unless they choose not to. Regardless, students are asked to go back to recall and review their operation for trouble shooting under the instructor’s (or TA’s) supervision, till they show competency in the experiment with reproducible and biologically meaningful data. Trouble shooting under instructor’s or TA’s supervision and inspiration serves as an efficient platform for students to take the lead in critical thinking and problem solving, which prompts students to go back to improve or update their protocols showing special and practical notes about potential pitfalls and success tips.

Often with delight, students realize how much they have grown at the end of experimentation. However, frustration is not uncommon during the troubleshooting and learning, which has to be overcome through students’ persistence and instructor’s encouragement. Some students might feel like “jumping off a cliff” in the early stage of an experiment where a ready-to follow instruction is not available. Growing in experience and persistence, they become more confident and open to pursue “why” in addition to “what”.

Of note, logistic consideration is critical to ensure active learning by this strategy. A single experiment would take up to 3-fold more time for the instructor and students to work together to reach competency. To this end, the instructor needs to reduce the number of experiments for a semester, and carefully select and design the key experiments to maximally benefit students in terms of skill learning, critical thinking, and problem solving. Furthermore, group size should be kept small (e.g., less than 3 students per group) to maximize interactive learning if independent experimentation by individuals is not an option. Such a requirement can be met either by increasing TA support or reducing class size.

Zhiyong Cheng is an Assistant Professor of Nutritional Science at the Food Science and Human Nutrition Department, University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS). Dr. Cheng received his PhD in Analytical Biochemistry from Peking University. After completing his postdoctoral training at the University of Michigan (Ann Arbor) and Harvard Medical School, Dr. Cheng joined Virginia Tech as a faculty member, and recently he relocated to the University of Florida. Dr. Cheng has taught Nutrition and Metabolism, with a focus on substrate absorption, transport, and metabolism. As the principal investigator in a research lab studying metabolic diseases (obesity and type 2 diabetes), Dr. Cheng has been actively participating in undergraduate and graduate research training.