  There is a significant underrepresentation of women in many Science,
Technology, Engineering, and Mathematics (STEM) majors and careers. Prior
research has shown that self-efficacy can be a critical factor in student
learning, and that there is a tendency for women to have lower self-efficacy
than men in STEM disciplines. This study investigates gender differences in the
relationship between engineering students' self-efficacy and course grades in
foundational courses. By focusing on engineering students, we examined these
gender differences simultaneously in four STEM disciplines (mathematics,
engineering, physics, and chemistry) among the same population. Using survey
data collected longitudinally at three time points and course grade data from
five cohorts of engineering students at a large US-based research university,
effect sizes of gender differences are calculated using Cohen's d on two
measures: responses to survey items on discipline-specific self-efficacy and
course grades in all first-year foundational courses and second-year
mathematics courses. In engineering, physics, and mathematics courses, we find
sizeable discrepancies between self-efficacy and performance, with men
appearing significantly more confident than women despite small or reverse
direction differences in grades. In chemistry, women earn higher grades and
have higher self-efficacy. The patterns are consistent across courses within
each discipline. All self-efficacy gender differences close by the fourth year
except physics self-efficacy. The disconnect between self-efficacy and course
grades across subjects provides useful clues for targeted interventions to
promote equitable learning environments. The most extreme disconnect occurs in
physics and may help explain the severe underrepresentation of women in
"physics-heavy" engineering disciplines, highlighting the importance of such
interventions.
