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TEACHING IN THE LABORATORY
Department of Biology, Loyola College in Maryland, Baltimore, Maryland 21210
Abstract
I developed an inquiry-based laboratory model that uses a central theme throughout the semester to develop in undergraduate biology majors the skills required for conducting science while introducing them to modern and classical physiological techniques. The physiology laboratory uses a goal-oriented approach, with students working cooperatively in small groups to answer basic biological questions. The student teams work to develop skills associated with experimental design, data analysis, written and oral communication, science literacy, and critical thinking. The laboratory curriculum is a research-based model that offers the advantage of students asking open-ended questions by use of a variety of techniques. For the students and instructor alike, this presents an exciting and challenging approach for learning physiology and basic biological principles. Another advantage of this laboratory model is that it is flexible and adaptable; the central theme can be any that the instructor chooses, and the goals and techniques developed are based on student and instructor needs and interests. Students who have completed this model at Loyola College in Maryland have become equipped with the skills essential for any area of the biological sciences and, most importantly, showed elevated excitement and commitment to learning.
Key words: active learning; research laboratory; undergraduate physiology
Cell and organismal physiology have undergone a revolution over the last two decades in terms of our understanding of physiological processes and mechanisms. Advances in research techniques, particularly through the use of molecular biology protocols, and improvements in teaching pedagogy have served as the foundation for these changes. Surprisingly, despite numerous reports (22–23, 25) urging faculty and institutions to address issues associated with educational reform in the sciences, many faculty have approached this ever-increasing knowledge base by elevating the load of information that each student should learn (1). The laboratories that accompany undergraduate general and comparative physiology courses serve as clear examples; laboratories are usually fact laden and noninquiry oriented, with cookbook activities that promote the learning of science facts but not of science process skills (8, 23). Such teaching practices are contrary to the opinions of most educators, who agree that the laboratory should promote basic and integrated process skills, independent thinking, and positive attitudes including curiosity and interest (3, 14, 19). In short, students need the opportunity to be engaged and active in their learning (19, 24): to do science rather than just learn about science.
The use of non-inquiry-based laboratories is only one factor potentially confounding the teaching of undergraduate physiology courses; the overuse of technology in the laboratory and classroom has become the most recent problem. Technological advances have swept through modern science laboratories and have become firmly implanted in physiology education. When used as part of an integrated approach to help students learn, computer-based technology has been an effective addition to the classroom and laboratory (10, 20). However, it is also apparent that overuse of technological aids can undermine student active learning. This is best illustrated by the increasing reliance on computer-based physiology simulations and laboratory activities. At some institutions, all or nearly the entire laboratory experience is dependent on computer models or data acquisition systems that eliminate live-animal models (3). Such computer-driven physiology laboratories tend to decrease student exposure to "live tissue" to such an extent that they have difficulty placing physiological concepts into a tangible context. These approaches limit the student’s ability to obtain a broad education in the field of physiology and are contrary to student’s desires to learn physiology by use of live-animal models (3). Additionally, if these laboratories are not designed carefully into the curriculum, only those students actively using the computer acquisition system in small group settings obtain a noticeable benefit, whereas other members of the group watch from the sidelines and become passive learners.
Are there solutions to these problems? Although all physiology educators do not agree on the solutions, or even the problems, there is a growing body of evidence and testimonials by teachers that certain practices yield desired learner outcomes. For example, student-centered, active approaches using inquiry-based laboratory activities have been shown to produce more of the skills associated with critical and independent thinking and increased student curiosity and motivation than more traditional approaches (11, 12, 20, 21). Additionally, the Project Kaleidoscope community (http://www.pkal.org), as well as common sense, tells us that technology cannot replace good teachers and teaching practices. So how can a balance be achieved between using technology in the classroom and laboratory and introducing students to the concepts, principles, and techniques of physiology, which seem to be changing so rapidly? In this article, I describe a new laboratory curriculum for an undergraduate Comparative Physiology course that tries to reach that balance.
COMPARATIVE PHYSIOLOGY COURSE
Course Description
Comparative Physiology at Loyola College in Maryland is a one-semester course that was designed to provide undergraduate students with a comprehensive introduction to the similarities and differences in the functional processes of animals at selected levels of phylogeny. The lecture course emphasizes the adaptive significance of life processes that have evolved as a consequence of an ever-changing environment. The laboratory component was developed to provide students the opportunity to be engaged in a research-based laboratory, using team strategies to answer questions about physiological processes and mechanisms. Students are also exposed to modern and classical techniques commonly used in physiological research.
Typically, students majoring in biology or chemistry enroll in the Comparative Physiology course during their junior or senior year. The course was designed for upper-level students who already have a significant background in biological principles (usually two years’ worth of courses), have completed two semesters of organic chemistry (this background is recommended but not required for enrollment), and have finished a two-semester biology sequence on experimental design and analysis, called Process of Science I and II. Most students enrolled in the course plan to attend medical school or obtain graduate training upon graduation from Loyola. Consequently, the course is typically filled with very bright, highly motivated students who have a genuine interest in the topics and/or techniques to be presented throughout the semester.
The course has an enrollment cap of 24, with actual enrollments ranging from 20 to 24 every spring semester for the past four years. Among these students, small groups (research teams) are formed with no less than three students per group and never more than four in a team.
Curricular Deficiency
In 1997, I began developing a new laboratory curriculum for an undergraduate comparative physiology course to address specific curricular concerns. Within the biology major at Loyola College, students were able obtain a strong background in physiological systems and mechanisms through courses such as General Physiology, Comparative Physiology, Endocrinology, Immunology, and Cell and Molecular Biology. However, the laboratories that traditionally accompanied these courses provided only a limited approach to inquiry-oriented activities, with some hands-on exercises, but that generally did not promote acquisition of science process skills. Students thus accumulated facts concerning physiology but did not acquire the skills to use that knowledge. This represented a considerable deficit in the department’s ability to provide a thorough education to our students in the field of physiology and, most importantly, in our students’ preparation for careers in any area of science.
Revision
The revised course uses a research-based model that builds on comparable activities that have been successfully implemented by Dr. Larry Wimmers (personal communication) at Towson University (Towson, MD). The new physiology laboratory uses a goal-oriented approach, with students working cooperatively in small groups to answer physiological questions. The student teams work to develop skills associated with experimental design, data analysis, written and oral communication skills, science literacy, and critical thinking. The curriculum also integrates classical and modern physiology techniques with live-animal models (vertebrate and invertebrate) and cultured animal cells (vertebrate and invertebrate). Computer-based data acquisition systems are used for some of the laboratories, but computer simulations have been reduced to study aids. Students who have completed the Comparative Physiology course generally display increased curiosity and motivation toward physiology and other topics in biology and are equipped with skills essential for any area of the biological sciences. This approach requires students to be active learners, because they must design and conduct their own experiments, analyze and interpret their data, and make the decisions on where to go next. Thus students are engaged in the process of science from the beginning of the semester until the end.
Inquiry-Based Laboratory Design: General Organization
The laboratory curriculum that was developed was designed specifically to address curricular deficiencies in the physiology courses at Loyola College, with the ultimate goal of implementing inquiry-based learning throughout the entire biology curriculum. With the aid of the National Science Foundation’s Instrumentation and Laboratory Improvement Program (DUE 97–50854), I developed a laboratory model that focused on a central theme (heat shock response) throughout the semester in an attempt to introduce physiological techniques and develop skills required for conducting science. Although there is no one teaching strategy that can be considered the best approach for biology laboratories, project-oriented laboratory courses have proved to foster desired learner outcomes (e.g., development of independent and critical thinking skills, positive attitudes, and curiosity toward science) more often than traditional, teacher-oriented approaches (8).
The techniques and topics selected for investigation were chosen with the goal of engaging students in the course, hopefully resulting in increased enthusiasm and curiosity for science as a whole. Students worked in small groups (3–4) to develop hypotheses and design experiments based on their own readings of primary research literature on topics (related to stress responses) selected by the instructor. Student teams generated miniproposals for each topic and then worked independently over a one- to two-week period to perform the experiments they designed, analyze and interpret the data, and then generate either individual or group reports. When experimental protocols exceeded the time expectations for the goal or required equipment or animals not readily available in the department, student groups met with the instructor to "brainstorm" on alternative approaches. This amounted to a roundtable discussion, a form of problem-based learning (26), in which the students and the instructor would work through primary research articles together to develop more feasible protocols and/or experimental designs for the hypotheses they had posed. Whenever a roundtable discussion occurred, it was expected to be student directed.
Objectives of the Inquiry-Based Laboratory
This approach to laboratory teaching/learning concentrates on the development of specific learning skills. Table 1 highlights activities used to develop the learning skills and techniques described below.
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Increased student interest in the course. Learning is always more likely to occur in students who are well motivated and interested in the subject. Student-centered, goal-oriented projects in the laboratory and classroom are known to lead to increased student motivation and commitment to the course (23). Elevated course commitment also fosters cooperation among students and increases the likelihood of peer tutoring.
Development of oral and written communication skills. Completion of scientific papers helps students develop and enhance their science communication skills, and, by serving as peer reviewers, they have a unique opportunity for comparison and self evaluation. Peer tutoring and peer review have been shown to be excellent methods to promote student learning (29), particularly in undergraduate physiology courses (13).
Development of abilities to work in team situations. Team strategies have become universal approaches in modern industrial and research laboratories, and experience in team situations is an important factor influencing hiring in industrial and research laboratories. Collaborative work also breaks down student isolation and allows for students with different strengths to play distinct roles (19).
Enhanced science literacy and critical thinking skills. Few undergraduates develop the ability to interpret scientific literature, and most find primary research articles difficult to comprehend and they fail to understand why a particular experimental approach was used in a study. The project-oriented laboratory improves and further develops the student’s ability to evaluate and critically analyze research articles, leading to application of ideas to their own projects, and being better able to place individual techniques in a tangible context. The processes associated with this learning skill also foster within each student the independent thinking skills required of biologists in almost every work situation.
Central Theme of the Laboratory Curriculum
The central physiological theme selected for student research projects involved the role of heat shock (stress) proteins in the restoration of homeostasis following an environmental stress such as hyperthermia or anoxia. Any topic can be selected for a theme-oriented laboratory as long as it is interesting to the students and the instructor has a strong familiarity with and interest in the topic and techniques typically used in investigations. For example, I have used two different topics for the course: seasonal adaptations and stress physiology. The latter has been the central topic for the Comparative Physiology laboratory most frequently (Table 2 gives an example of a laboratory syllabus), largely because my students and I have found it more interesting, which is a critical factor influencing learning and motivation when a theme-based approach is used. Additionally, some topics are better suited than others for developing laboratory investigations that combine modern and classical physiological techniques. Table 3 highlights the techniques used for the stress physiology theme. Again, the key to topic selection is the instructor; what works for one instructor/course may not work for another. However, the basic framework of this laboratory model is well suited for a multitude of biological topics, techniques, and variations on model design.
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Implementation of the Laboratory Model
The project-oriented laboratory concentrates on completion of specific project goals rather than a week-by-week list of specific exercises. Many of the project goals require one to two weeks to complete, and the techniques used may overlap. In Table 1, I describe the project objectives and the physiological techniques most commonly used to address each question. This laboratory approach can be organized in numerous ways, and Table 2 reflects the one I have used most recently. As stated previously, each of the project objectives is designed to reinforce a specific concept of physiology, develop multiple learning skills, and provide practical experience in the use of physiological techniques. In many cases, there are several techniques that can be used to accomplish each project goal. These methods range from classical approaches using force transducers or surface electrodes to more involved techniques incorporating molecular biology protocols (e.g., protein electrophoresis and DNA extractions and separations). The techniques and skills introduced to students examining stress physiology in my most recent course are identified in Table 3 and also include resources on how to perform basic and advanced methods related to specific project goals. My goal in selecting these methods was to strike a balance between introducing modern and classical physiology techniques with approaches most useful for helping students learn and gain practical skills for their potential careers.
At semester’s end, student teams are given the chance to put their newly acquired skills to use by designing an open-ended research project related to the course’s central theme. Research teams pose a question associated with stress physiology, form hypotheses, design experiments using the primary literature, and collect and analyze the data. Examples of these student projects for the last three years are presented in Table 4. The projects typically last three to four weeks, with students given open access to the laboratory and equipment needed, day or night, seven days a week. Routinely, student groups would meet with me to have roundtable discussions about the experimental design, data collected, and types of analyses to perform. At least once a week during the lecture component of Comparative Physiology, the class as a whole would get updates about the various student projects from each group. Frequently, this would also lead to whole-class roundtable discussions, particularly when a group was struggling with the next step to take for their project. In most situations, a student from another team would offer a suggestion that would stimulate new ideas in the group that was asking for help.
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DOES THIS LABORATORY MODEL WORK?
In a follow-up paper, I will present a detailed assessment of this laboratory model with the use of four years of data from students enrolled in my Comparative Physiology course. For now, I will offer a few qualitative observations/opinions. Acquisition of content is not a primary goal of the project-oriented laboratory. My philosophy for the physiology laboratory is that it is better for students to concentrate on performing fewer tasks well than to be concerned with completing all of the goals originally established at the beginning of the semester. This means that, although a detailed list of project goals is on the course syllabus, it is not essential for student teams to complete all of the objectives (nor is the course grade dependent on this). If the students achieve increased proficiency in the learning skills identified, then in my opinion the laboratory model is a success. At this point, all measures of assessment that I have used indicate that this indeed is occurring with nearly all students who complete the course.
There are some drawbacks to using a theme-based approach in an undergraduate physiology course. For example, the curriculum detailed is demanding on the instructor in that one must make large blocks of time available to the student teams each day and be ready for unexpected twists and turns in student-designed projects. As well, the instructor must be open to the challenges of advising student projects that are not the same in terms of complexity, techniques, or test subjects and be highly organized in terms of space, equipment availability, and materials needed to perform several projects at once. This approach to the laboratory also necessitates relatively small class sizes (I have not used it for more than 24 students/lab section) and can be expensive to run depending on the central theme chosen for the semester.
With all the concerns raised above, does such a laboratory model warrant consideration for implementation in an undergraduate curriculum? Based on the results observed in terms of enhancement of student thinking and writing skills, willingness and ability to work with other students to solve problems, and the increased enthusiasm for biology, my answer is unequivocally yes. As mentioned at the outset, there is certainly no single method that can be considered or has been shown to be the best for teaching science laboratories. The project-oriented, inquiry-based physiology laboratory described in this paper does show tremendous promise to achieve the desired learner outcomes being advocated by many science educators and government agencies (2, 5–6, 12, 14). Most importantly, students who have completed this laboratory curriculum seem better equipped to use the knowledge and skills associated with physiology and biology than students taught by more traditional styles. Additionally, students generally appeared to enjoy the process of learning and thus are more likely to be motivated and committed to learning in subsequent endeavors.
Acknowledgments
I am grateful to Drs. Charles Graham and Donald Keefer, and Eugene Meyer (Department of Biology, Loyola College) for the many conversations on teaching innovations in biology.
Development of the Comparative Physiology laboratory curriculum was supported by funding from the National Science Foundation’s Instrumentation and Laboratory Improvement Program (DUE 97–50854) and Loyola College in Maryland.
Address for reprint requests and other correspondence: D. B. Rivers, Dept. of Biology, Loyola College in Maryland, 4501 N. Charles St., Baltimore, MD 21210 (E-mail: drivers{at}loyola.edu).
Received for publication January 4, 2002. Accepted for publication August 29, 2002.
REFERENCES
This article has been cited by other articles:
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  A. M. Dantas and R. E. Kemm A blended approach to active learning in a physiology laboratory-based subject facilitated by an e-learning component Advan Physiol Educ, March 1, 2008; 32(1): 65 - 75. [Abstract] [Full Text] [PDF]
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D. B. Luckie, J. J. Maleszewski, S. D. Loznak, and M. Krha Infusion of collaborative inquiry throughout a biology curriculum increases student learning: a four-year study of "Teams and Streams" Advan Physiol Educ, December 1, 2004; 28(4): 199 - 209. [Abstract] [Full Text] [PDF]
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