Professor of Mechanical Engineering University of Maryland Baltimore County BALTIMORE, Maryland, United States
Introduction:: Mechanical Engineering (ME) courses have been viewed as challenging by many students, leading to low retention rates [1] in our ME undergraduate program. Lack of blocks of time for course work is a common issue experienced by our students due to their part-time jobs and commuting to the campus [2]. In the past several semesters, we assigned bonus problems in undergraduate heat transfer class to encourage students to use their fragmented time on the course contents. This retrospective study evaluates the correlation between students’ participation in the bonus problems and their course performance.
Materials and Methods:: In the Spring 2022 semester heat transfer course, we assigned 11 bonus problems (adding 3 extra points to the final scores). They are questions directly related to their daily life. Example questions (Figure 1a) include “How to lose weight without eating less and/or exercising more? What is the scientific definition of wind chill temperature? What are the reasons that cause a smaller day-night temperature difference in Baltimore than that in a desert?”. Students submitted a page of derivations, calculations, and discussion for each bonus assignment. The participation rates and students’ grades were from the course records. Students’ overall GPAs before the semester were obtained from the university’s database. The difference between the student’s grade of the course (A=4, B=3, C=2, D=1, F=0) and his/her overall GPA before the semester (baseline status) was used to evaluate the impact of the bonus problems on students’ mastery of technical contents. 78 students finished the course.
Results, Conclusions, and Discussions:: Figure 1b shows that the students’ overall GPAs before the semester correlate slightly with the number of bonus submissions. Among the 78 students, 56% of students submitted at least 1 bonus problem, and 14% of the students submitted at least 6 bonus problems. The participation rates of the students who got a grade of C or worse were much lower than the students who got a grade of A or B. The difference between the student’s course grade and the overall GPA before the semester is plotted in Figure 1c. For students who submitted 0-2 bonus problems, their course grades were 0.6 - 0.86 lower than their overall GPA, indicating poorer performance than their baseline status. For the students who submitted at least 3 bonus problems, their performance was similar to (groups 4-6) or better than (group 9) their baseline status. The trendline in Figure 1c shows a positive slope, implying better performance in the course associated with more participation in the bonus problems.
Acknowledgements (Optional): : This research was supported by an NSF S-STEM grant (DUE-1742170).
References (Optional): : 1. Zhu et al., ASME Journal of Biomechanical Engineering, 143(12): 121006 (1-7), 2021. 2. Kyndt et al., Higher Education Research & Development, 33(4), 684-698, 2014.