This study uses two annual cohorts of students from a large, public, midwestern research institution to implement a propensity-based analysis of a student support program called Supplemental Instruction. Beginning with the history and importance of improving college completion (i.e. graduation) rates, this study identifies student support programming as an increasingly utilized and funded effort on many college campuses. However, most programs produce only descriptive statistics, or otherwise flawed outcome assessments, regarding their effectiveness. One major issue with assessments of effectiveness is that they fail to account for baseline differences in self-selecting populations versus the students who choose not to participate. Utilizing data available via a university student information system, as well as a survey issued by one college within the university, this study introduces propensity-matched analyses as one possible approach for redressing methodological issues within the student support programming literature. Pilot analyses across the first cohort of students explore variables relevant to the construction of propensity scores, to include scores and items taken from the Grit-O assessment, developed by Duckworth et al. (2009). A final propensity-score analysis is executed using the second cohort of students. Findings from this model, as well as considerations for practitioners seeking to institute more rigorous assessments of student support programs and recommendations for future research are addressed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]