2020 ASEE Virtual Annual Conference Content Access

This work in progress paper outlines our planned study of students’ conceptual understanding of signals and systems. Signals and systems (SS) is the focus of an electrical engineering (EE) science course at most universities, and topics in SS - such as filtering and Fourier transforms - are fundamental to control theory, signal processing, and machine learning tracks in EE. Despite the importance educators place on SS concepts, previous studies have shown that students understand few of the concepts at the end of a SS course. The purpose behind our planned study is to determine if undergraduate students learn individual SS concepts, and, if they do, when and how.

There are few studies that report on students’ conceptual understanding of SS topics one or more semesters after a SS course. This study aims to help fill this gap by examining student conceptual understanding over time. Our research questions are:
(1) How many and which concepts do students learn during their signals and systems class?
(2) How many and which SS concepts have students learned, retained, or forgotten as of their fourth year of undergraduate studies?
(3) What factors influence the answers to the first two questions?

We will be studying undergraduate engineering students at the University of Michigan and University of Virginia during their second through fourth years. To measure conceptual understanding (research questions 1 and 2), we will use the signals and systems concept inventory (SSCI), an existing, validated 25-question multiple-choice test. Student participants will take the SSCI up to three times: the beginning and end of their SS course and the beginning of their fourth year.

Based on a literature review and our own experiences with SS, we have expectations for what factors may influence student conceptual understanding, e.g., what elective courses students take, whether students have seen a topic outside of a course, and what career options students are considering. Based on this and a qualitative analysis of focus groups that we will conduct with students, we will design a survey to measure factors which might impact conceptual understanding. A statistical analysis of this data, in conjunction with SSCI scores, will help answer research question 3.

Our goal for this study is to help educators understand how the undergraduate curricula (beyond just the SS course) is or is not meeting what we want undergraduate EE students to understand when they graduate and what could be changed to increase understanding. While we have chosen to study SS conceptual understanding, we anticipate our study will provide insights into the conceptual understanding over time in other engineering disciplines.

This work in progress paper will outline our planned methodology, describe the theories that will influence our study, and present preliminary results. Our goal is to receive feedback from the community on possible factors that influence long-term conceptual understanding to include on our surveys and to see if anyone else has, or wants to collect, SSCI data from fourth years to add to the data analysis.