Limited time and resources require educators to be more efficient with the interventions they implement with students. A reliable system of interventions that efficiently improves student achievement eliminates the threat of wasted time and provides a safety net of support to ensure a higher probability of future success. This study examines the relationship between a system of interventions and student achievement in one school district. More specifically, 1) does individual or multiple interventions have a greater impact on student outcomes, 2) does the degree of implementation of a system of interventions have an impact on student outcomes, and 3) what are educators' perceptions about the effectiveness of the interventions? To explore these questions, this mixed-methods study used both qualitative and quantitative data for analysis. Factor analysis narrowed down results from an educator survey about intervention implementation, and a repeated measures ANOVA compared each factor to student achievement scores. Results suggest MTSS Implementation, Tier II Implementation, Intervention Reflection, Self-Efficacy, and Belief in the Problem-Solving Process all influenced student outcomes in the current study. A proposed model of systems implementation was provided that emphasized 1) the need for teacher buy-in, 2) a shift from a passive to active implementation process and 3) and emphasis on using both evidence-based interventions paired with an evidence-based implementation process. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]