Improving Conceptual Understanding of Signals and Systems in Undergraduate Engineering Students Using Collaborative In-Class Laboratory Exercises

Three MATLAB-based in-class collaborative laboratory exercises were introduced in conjunction with the traditional lecturing and problem-solving techniques in the signals and systems course at Vanderbilt University. These labs were developed to enhance students' conceptual understanding and retention using MATLAB simulations of audio synthesis and processing, using guitar notes as signals and processing these signals through linear time-invariant (LTI) systems to produce sound effects. The impact of the new curriculum on students' conceptual understanding was evaluated through three techniques - quantitative assessment using the Signals and Systems Concept Inventory (SSCI), and qualitative assessment using a voluntary end-of-semester lab survey and a small group analysis. Analysis of SSCI scores from the first batch of students in the new curriculum indicated a course average normalized gain of 0.54 in the discrete time SSCI and 0.61 in the continuous time SSCI student performance. Student agreement on the labs (reinforcing the concepts of signal transforms and visualization, convolution and filtering) correlated well to their actual SSCI scores on questions based on these concepts. Analysis of subtest topics suggested persistence of common misconceptions, thereby motivating suitable changes to the lab exercises to be implemented in future semesters. Student performance and responses indicated that the collaborative laboratory exercises improved student learning and also suggested areas for improvement in the lab exercises for future semesters.