UC Irvine

Patching the “leaky STEM pipeline” has been central to increasing the STEM labor supply as well as the gender balance of the STEM workforce. Recently, criticisms have accumulated about the limitations and the stigma conveyed by this metaphor. Yet, there lacks evidence on STEM career paths to examine to what extent and in what ways the “leaky pipeline” metaphor represents STEM career trajectories accurately. Previous studies have shown STEM entry as an alternative pathway into STEM careers and as a venue to address the gender gap in STEM degree attainment. More research is needed to further understand the profiles of people entering STEM fields at a later time point. The Situated Expectancy-Value Theory indicates that STEM career choices are linked to individual differences in the motivation about the STEM and non-STEM domains. More specifically, individuals evaluate the career choices available to them at a given point in time and choose one ranked among the highest in their hierarchy of options. The Dimensional Comparison Theory further elaborates on this inter-personal comparison, with evidence showing its implications on the formation of expectancy-value beliefs and achievement choices in different domains. To what extent understanding based on these theories about achievement-related choices at one point in time can be applied to career trajectories over time requires further examinations. Most of the studies in this area were based on quantitative data analyzed in a confirmatory manner. Evidence is needed to demonstrate to what extent the motivational processes described in the Situated Expectancy-Value Theory occur in the spontaneous process of an individual’s career decision-making. To address these gaps in the literature, I attempted to describe and explain changes in STEM career paths in the three studies of this dissertation. In study one, I used a national, longitudinal sample to describe the existing STEM career trajectories from age 13 to 25. I plotted men’s and women’s career paths in the broad STEM field, as well as in the health STEM domain and the physics-related STEM domains. I included the often-overlooked distinction among STEM careers regarding the education requirement, between the blue-collar STEM jobs and the white-collar STEM jobs. My graphs and analyses visualized the much-studied STEM career trajectories and provided evidence for the limitations of the “leaky pipeline” metaphor. In study two, I used logistic regressions to examine the sociodemographic, achievement and motivational factors of the STEM entry and the STEM attrition. Results showed meaningful differences between individuals taking different trajectories. In study three, I used students’ open-ended responses to understand the reasons for changes in their major plan in college introductory STEM courses. The results demonstrated that expectancy-value beliefs were a natural part of students’ considerations, and that different beliefs may play roles in different types of changes in career paths. In sum, findings from the three studies supported the gender differences and more broadly, individual differences in STEM career paths and pointed to the developmental roots of these trajectories.