Date of Award

8-22-2025

Date Published

9-18-2025

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Science Teaching

Advisor(s)

John Tillotson

Second Advisor

Jason Wiles

Keywords

graduation;low income;retention;STEM Education;STEM Intervention Program;undergraduate

Abstract

Persistent disparities in Science, Technology, Engineering, and Mathematics (STEM) degree completion and career attainment continue to disadvantage students from low-income, firstgeneration, and underrepresented racial and ethnic backgrounds, despite sustained national efforts to diversify the STEM workforce. STEM Intervention Programs (SIPs) have emerged as promising strategies to address these inequities, yet limitations in SIP evaluation literature including the lack of comparison groups, limited longitudinal data, and minimal attention to psychosocial outcomes impede our understanding of their long-term impact. This dissertation uses a mixed-methods, three-project design to evaluate the Strategic Undergraduate STEM Talent Acceleration INitiative (SUSTAIN), a comprehensive SIP at a private, Predominantly White Institution (PWI) in the northeastern United States, serving high-achieving, low-income STEM undergraduates. Project 1 uses institutional data to assess academic disparities in STEM prior to and after SUSTAIN implementation. Part one this project (Chapter 1) establishes a baseline by comparing GPA and STEM graduation outcomes by income status among pre-SIP cohorts (2014–2016). Results indicated no statistically significant difference in GPA or six-year graduation rates between groups, but low-income students were significantly more likely to require more than four years to complete their degree. Part two of Project 1 (Chapter 2) evaluates outcomes for the first SUSTAIN cohort (2017) relative to matched low- and high-income peers, using regression analyses to assess effects on GPA, time to degree, and STEM graduation rates. SUSTAIN participants had comparable graduation rates and GPA to their higher-income peers and outperformed their lowincome peers, especially in terms of time-to-degree completion. Project 2 (Chapter 3) investigates changes in “identity as a scientist” during the first year of college, comparing SUSTAIN participants to STEM peers using a two-way mixed ANOVA. Results reveal that SIP participants began college with higher identity scores that remained stable over time, while comparison students demonstrated significant gains, suggesting the program buffered against potential identity decline. Project 3 (Chapter 4) explores career outcomes for the original SUSTAIN cohort using a convergent mixed-methods design. Follow-up surveys and in-depth interviews conducted 3–5 years post-graduation revealed that participants’ STEM trajectories were shaped by structural barriers, mentoring and support networks, evolving interests, and personal growth in science identity and self-efficacy. Together, these three projects provide a multidimensional evaluation of an SIP’s impact on both academic and psychosocial outcomes, including STEM degree attainment, identity development, and career pathways. The findings inform more equitable program design and policy recommendations, including the need to reconsider merit-based eligibility and expand definitions of STEM success beyond degree completion to include translational, interdisciplinary, and policy-related careers.

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Open Access

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