Zhang, Yue2023-03-272023-03-272022-12https://hdl.handle.net/11299/253428University of Minnesota Ph.D. dissertation. December 2022. Major: Organizational Leadership, Policy, and Development. Advisor: Stuart Yeh. 1 computer file (PDF); viii, 185 pages.There is a need to address disparities in the underrepresented minority (URM) STEM students’ degree attainment and retention, vs. non-URM students. A literature review suggests that URM STEM students face barriers related to demographic, academic, and social-cognitive factors. The Louis Stokes North Star STEM Alliance (LS-NSSA) seeks to address these factors and promote URM student success in STEM disciplines. However, there is a gap in knowledge regarding LS-NSSA’s mechanism and outcomes. The current study investigates factors influencing URM STEM students’ retention and graduation, investigates LS-NSSA program effectiveness, and investigates the path by which outcomes are achieved. A theory-based evaluation approach is utilized in an explanatory sequential mixed-methods design guided by LS-NSSA’s theory of change. The results of three sub-studies suggest the importance of first-semester experience and academic outcomes for URM STEM students’ graduation and retention. Participation in LS-NSSA is associated with a higher level of academic preparation to pursue a bachelor’s degree, compared to URM students not affiliated with the program. URM STEM students participating in LS-NSSA’s research mentorship programs have higher levels of confidence, interest, science identity, sense of belonging, and commitment to STEM. The current study offers evidence supporting LS-NSSA’s theory of change regarding student academic and social-cognitive trajectories. The current study suggests directions for future evaluative studies of LS-NSSA.enmixed methodsretention and degree attainmenttheory of changetheory-based evaluationURM STEM studentsThesis or Dissertation