Active Learning in Electrical Engineering: Measuring the Difference

Engineering Electromagnetics is a challenging junior-level course containing many concepts and formulae, and is a core course in many Electrical Engineering programs. A traditional way to teach this class is via direct instruction, i.e., didactic lecture. The instructor often introduces the concepts and then works examples for the students. While the process of working examples may be helpful to some students, at Texas State University the question arose as to whether or not actively engaging the students would improve their understanding of the material. To address this hypothesis, raw exam scores were examined for a total of four semesters. In the first two semesters of the study only direct instruction was used. The next two semesters used active learning with direct instruction for the first half of the class period, working no examples, and then had students collaboratively solve examples and problems for the second half of the class. Students were strongly encouraged to work together in teams and to discuss the material while the instructor circulated to give guided practice. Solutions became visible 15 minutes before the end of the class period via the learning management system so that students could check their level of understanding. These in-class exercises, in the form of worksheets, were worth one and one-half letter grades. Pre and post course instructional style student knowledge was measured by comparing normalized raw scores on four exams for each semester consisting of three exams and a final. Each exam covered the same topics, for example, the first exam was concerned with transmission lines, the second exam tested for knowledge of electrostatics and magnetostatics, and so forth. While the exams differed from semester to semester by changing values, boundary conditions, or solving for a particular variable, the exams were substantially similar in content, number of questions, and number of concepts tested. While student grades were determined by scaling the exam scores, the extent of their content mastery for purposes of this analysis was performed by comparing normalized raw scores. Subsequent analysis revealed that there was an improvement both in mean raw score and in standard deviation of score. For example, the mean exam raw score before active learning was 55.9% with a standard deviation of 18.6% (62 students) vs. a mean of 66.6% with a standard deviation of 17.6% (62 students) after active learning was implemented. The p-value was <.001 indicating better than 99% confidence. While the standard deviation improved by 1%, the mean increased from 55.9% to 66.6% which is an entire letter grade. Introduction and Background Traditional instruction by lecturing in the classroom has been the dominant role in University education for over a millennium [1]. Changes to the instructional method should be considered in order to improve the engineering classroom learning experience. Active learning is an approach developed to improve student learning outcomes, and typically consists of techniques requiring students (as the name implies) to be actively engaged in learning through specially designed activities, followed by reflection upon, often in groups, what they have done [2]. There is considerable literature that addresses the advantages of using hands-on experiences in engineering and STEM curricula [3]-[8]. While Active learning has been shown to increase student performance in STEM classes [9], many still do not implement active learning in the classroom. Collaborative learning is one form of active learning that can be implemented in the classroom and it has been practiced and studied since the early 1900s. The principles are based on the theories of Bloom's taxonomies, Vygotskian perspectives, Dewey’s Hands-on learning [10]-[12]. Their efforts resulted in a focus on student-centered learning. Can a relatively simple change from a class comprised of all lecture to one with the class period split between lecture and collaboratively solving problems in a group, be sufficient to see gains in student learning, as have other implementations of active learning? This study is an application of active learning through collaborative learning between students in a junior-level electrical engineering course, Engineering Electromagnetics. Engineering Electromagnetics Course Electrical engineering undergraduate students typically must complete a Physics course on electricity and magnetism, and many universities additionally require a course in engineering electromagnetics. At Texas State University this course provides a review of the physics of electricity and magnetism then proceeds to emphasize the engineering aspects and applications of electromagnetics for the remainder of the semester. The application of electromagnetics and its impact upon modern society is stressed to students by comparing their current society connectivity and conveniences to the mid-1850's. As currently taught, this electromagnetics course consists of four modules, each with an associated free-response examination: 1. Transmission lines and matching, and transient effects (6 class periods) 2. A review of electrostatics and electromagnetics (5 class periods) 3. Maxwell's equations, propagation, transmission, reflection and refraction (7 class periods) 4. Waveguides, antennas, satellites, communication links and radar (6 class periods) Accordingly, the first module is assessed in Exam 1, the second module in Exam 2, the third module in Exam 3, and the fourth module in the Final Exam. This class met a total of 27 times per semester, and consisted of an 80 minute lecture in which the instructor worked three to five examples. Homework problems were assigned from the textbook, which has remained the same through the eight times in which this instructor has taught this class. The class also included two Python programming assignments. The first was to calculate the input impedance of a transmission line versus distance and the second to calculate the propagation parameters of various materials at a given frequency.