Zhiyong Cheng, PhD
Food Science and Human Nutrition Department
The University of Florida
Development of critical thinking and problem-solving skills hallmarks effective teaching and learning [1-2]. Physiology serves as a fundamental subject for students in various majors, particularly for bioscience and pre-professional students [1-8]. Whether they plan on careers in science or healthcare, critical thinking and problem-solving skills will be keys to their success [1-8].
Backwards course design is increasingly employed in higher education. To effectively accomplish specific learning goals, instructions are to begin course development with setting learning objectives, then backwardly create assessment methods, and lastly design and deliver teaching and learning activities pertaining to the learning objectives and assessment methods. In terms of development of critical thinking and problem-solving skills, a lab course constitutes an excellent option to provide opportunities for instructors and students to explore innovative paths to their desired destinations, i.e., to accomplish specific learning goals.
In a traditional “cookbook” lab setting, detailed procedures are provided for the students to follow like cooking with a recipe. Students are usually told what to do step-by-step and what to expect at the end of the experiment. As such, finishing a procedure might become the expected goal of a lab course to the students who passively followed the “cookbook”, and the opportunity for developing critical thinking skills is limited. In a backwards design of a lab course; however, the instructor may engage the students in a series of active learning/critical thinking activities, including literature research, hypothesis formulation, study design, experimental planning, hands-on skill training, and project execution. Practically, the instructor may provide a well-defined context and questions to address. Students are asked to delve into the literature, map existing connections and identify missing links for their project to bridge. With the instructor’s guidance, students work together in groups on hypothesis development and study design. In this scenario, students’ focus is no longer on finishing a procedure but on a whole picture with intensive synthesis of information and critical thinking (i.e., projecting from generic context to literature search and evaluation, development of hypothesis and research strategy, and testing the hypothesis by doing experiments).
An example is this lab on the physiology of fasting-feeding transitions. The transition from fasting to feeding state is associated with increased blood glucose concentration. Students are informed of the potential contributors to elevated blood glucose, i.e., dietary carbohydrates, glycogen breakdown (glycogenolysis), and de novo glucose production (gluconeogenesis) in the liver. Based on the context information, students are asked to formulate a hypothesis on whether and how hepatic gluconeogenesis contributes to postprandial blood glucose levels. The hypothesis must be supported by evidence-based rationales and will be tested by experiments proposed by students with the instructor’s guidance. Development of the hypothesis and rationales as well as study design requires students to do intensive information extraction and processing, thereby building critical thinking and problem-solving skills. Students also need to make sound judgments and right decisions for their research plans to be feasible. For instance, most students tend to propose to employ the hyper-insulinemic-euglycemic clamp because the literature ranks it as a “gold standard” method to directly measure hepatic gluconeogenesis. However, the equipment is expensive and not readily accessible, and students have to find alternative approaches to address these questions. With the instructor’s guidance, students adjust their approaches and adopt more accessible techniques like qPCR (quantitative polymerase chain reaction) and Western blotting to analyze key gluconeogenic regulators or enzymes. Engaging students in the evaluation of research methods and selection helps them navigate the problem-solving procedure, increasing their motivation (or eagerness) and dedication to learning new techniques and testing their hypotheses. Whether their hypotheses are validated or disproved by the results they acquire in the end, they become skillful in thinking critically and problem solving in addition to hands-on experience in qPCR and Western blotting.
Evidently, students can benefit from backwards planning in different ways because it engages them in problem-based, inquiry-based, and collaborative learning — all targeted to build student problem solving skills [1-8]. For a typical lab course with pre-lab lectures; however, there is only 3-6 hours to plan activities. As such, time and resources could be the top challenges to implement backwards planning in a lab course. To address this, the following strategies will be of great value: (i) implementing a flipped classroom model to promote students’ pre- and after-class learning activities, (ii) delivering lectures in the lab setting (other than in a traditional classroom), where, with all the lab resources accessible, the instructor and students have more flexibility to plan activities, and (iii) offering “boot camp” sessions in the summer, when students have less pressure from other classes and more time to concentrate on the lab training of critical thinking and problem solving skills. However, I believe that this is a worthwhile investment for training and developing next-generation professionals and leaders.
References and further reading
 Abraham RR, Upadhya S, Torke S, Ramnarayan K. Clinically oriented physiology teaching: strategy for developing critical-thinking skills in undergraduate medical students. Adv Physiol Educ. 2004 Dec;28(1-4):102-4.
 Brahler CJ, Quitadamo IJ, Johnson EC. Student critical thinking is enhanced by developing exercise prescriptions using online learning modules. Adv Physiol Educ. 2002 Dec;26(1-4):210-21.
 McNeal AP, Mierson S. Teaching critical thinking skills in physiology. Am J Physiol. 1999 Dec;277(6 Pt 2):S268-9.
 Hayes MM, Chatterjee S, Schwartzstein RM. Critical Thinking in Critical Care: Five Strategies to Improve Teaching and Learning in the Intensive Care Unit. Ann Am Thorac Soc. 2017 Apr;14(4):569-575.
 Nguyen K, Ben Khallouq B, Schuster A, Beevers C, Dil N, Kay D, Kibble JD, Harris DM. Developing a tool for observing group critical thinking skills in first-year medical students: a pilot study using physiology-based, high-fidelity patient simulations. Adv Physiol Educ. 2017 Dec 1;41(4):604-611.
 Bruce RM. The control of ventilation during exercise: a lesson in critical thinking. Adv Physiol Educ. 2017 Dec 1;41(4):539-547.
 Greenwald RR, Quitadamo IJ. A Mind of Their Own: Using Inquiry-based Teaching to Build Critical Thinking Skills and Intellectual Engagement in an Undergraduate Neuroanatomy Course. J Undergrad Neurosci Educ. 2014 Mar 15;12(2):A100-6.
 Peters MW, Smith MF, Smith GW. Use of critical interactive thinking exercises in teaching reproductive physiology to undergraduate students. J Anim Sci. 2002 Mar;80(3):862-5.
Dr. Cheng received his PhD in Analytical Biochemistry from Peking University, after which he conducted postdoctoral research at the University of Michigan (Ann Arbor) and Harvard Medical School. Dr. Cheng is now an Assistant Professor of Nutritional Science at the University of Florida. He has taught several undergraduate- and graduate-level courses (lectures and lab) in human nutrition and metabolism (including metabolic physiology). As the principal investigator in a research lab studying metabolic diseases (obesity and type 2 diabetes), Dr. Cheng has been actively developing and implementing new pedagogical approaches to build students’ critical thinking and problem-solving skills.