Effectiveness of Challenge-Based Instruction in Biomechanics

Journal of Engineering Education, Oct 2006 by Roselli, Robert J, Brophy, Sean P

E. Objectives of this Study

Since some studies report that engineering students generally prefer passive lectures to active learning methods, and since some PBL studies indicate negative effects when student knowledge was assessed, we were concerned that CBI might suffer similar difficulties. Less time is available in the classroom for lectures in CBI and other active learning environments. Does this in-class trade-off between lectures and CBI activities result in diminished performance and deflated student attitudes toward learning? Or, does this trade-off actually favor the CBI mode, particularly in regards to some of the more difficult concepts where more class time may be spent discussing these topics? In this paper we attempt to answer these questions.

We hypothesize that students in a CBI class can devote more inclass time toward clarification of concepts, particularly the more difficult concepts. Therefore, we would expect them to perform better than the control group on conceptually difficult knowledge-based questions asked near the end of the course. We addressed this by comparing students' performance on final exam questions in different sections of the same course taught with two different instructional methods over a period of three years. One section was taught by an instructor using a more traditional instructional method, while the other section was taught by another instructor using a challenge-based instructional design method. The issue of student perceptions of instructional methods was addressed by comparison of student course ratings for a single instructor before and after implementation of CBI, and by evaluation of surveys conducted in CBI classes.

II. METHODS

BME 101, an introductory course in biomechanics required of all biomedical engineering sophomores at Vanderbilt University, was selected for the comparison of traditional and CBI modes of instruction. The course provides students with the fundamental principles of statics, dynamics, and strength of materials as applied to biological systems and medical devices. The desired outcome for the course is for all students to be able to analyze and compute forces acting on biological systems and devices and identify their effects on system behavior.

A. Control: "Traditional" Mode of Instruction

BME 101 was taught in the traditional instructional model by the lead author from 1988 to 1999 and is currently taught that way by other instructors in the department. The traditional instructional model consists of lectures and instructor-centered problem-solving demonstrations during the class period, followed by student problem-solving activities after class. The lectures generally cover material in the same sequence as they are outlined in the textbook. The first quarter of the semester is devoted to reviewing fundamental concepts in vector mechanics, introducing students to the essentials of anthropometry, and an overview of musculoskeletal system physiology. The remainder of the course is devoted sequentially to biomechanics applications in statics, dynamics, and strength of materials. The traditional instructional model provides a learning environment that centers largely on transmitting domain knowledge from the professor to the students via lecture, followed by assessment of students' learning at the end of each unit.