2025 ASEE Annual Conference & Exposition

The underrepresentation of women in engineering continues to be a significant challenge. As of 2021, women comprised only 31% of environmental engineers in the U.S. While there has been an increase in the number of women pursuing engineering degrees and careers, gender disparities in performance and representation continue to persist. Addressing these disparities requires a deeper understanding of gender dynamics in undergraduate education, where foundational engineering skills are developed.

In this study, we collected data of 598 students enrolled in an introductory course, Environmental Engineering, over eight semesters (2015-2023), taught by the same female instructor. In this course, collaborative learning strategies were implemented to enhance peer instruction. Learning groups of 3-5 students were assigned, with the guiding principle of avoiding gender imbalance that could marginalize female students. These groups worked together weekly on problem sets, submitting a single solution for grading, with all group members receiving the same grade. Students were assessed individually using weekly quizzes and three exams.

This retrospective study performed quantitative analyses to investigate 1) gender-based performance difference across various assessments; 2) the influence of the gender composition of collaborative learning groups on individual student performance; 3) the impact of academic level on performance outcomes.

Our findings showed that the percentage of female students enrolled in the course increased from 25% in 2015 to 51% in 2023. Using grade point average (GPA) as a performance indicator, a two-sample t-test revealed no significant difference in overall performance between male and female students (p = 0.28) across all semesters aggregated. To assess the impact of group gender composition, students were categorized as females in single-gender groups, females in mixed-gender groups, males in single-gender groups, and males in mixed-gender groups. Analyses of variance (ANOVA) with Tukey’s honest significantly difference (HSD) tests were performed using problem set scores as the direct reflection of collaborative learning outcomes. Our findings revealed that female students in mixed-gender groups performed significantly better than those in single-gender groups (p = 6.8×10-6), while no significant difference was found between males in single and mixed-gender groups (p = 0.27), or between female and male students in mixed gender group (p = 0.94).

Similarly, ANOVA analyses with Tukey’s HSD tests of GPA by academic level indicated that prior academic experience influenced performance. Graduate students and seniors performed better than sophomores (p = 0.038 and p = 0.0049, respectively), though no significant difference was observed between sophomores and juniors (p = 0.23).

In conclusion, no significant gender difference was observed in the overall course performance. However, group dynamics played a crucial role in collaborative learning settings, and stage of education could influence student success. The finding that female students performed better in mixed-gender groups aligns with previous studies on both K-12 engineering education and college economic decision-making, which advocates for the use of mixed-gender learning groups for improved outcomes. Our findings provide valuable insights for the design of inclusive and effective learning environments in engineering education, recognizing the importance of addressing factors beyond gender composition to foster equitable and supportive academic experiences.