Without the development and implementation of appropriate reforms directed by school district leaders, struggling schools may continue to achieve low scores on state-wide evaluations. Addressing this issue requires cooperation between administrators to identify areas of need, develop a plan of action for change, and implement and monitor a shared vision (DuFour, Dufour, Eaker, & Karhanek, 2010) for reform. The researcher applied the theory of change (Weiss, 1995) as a theoretical framework to discover the change process taken by a Pennsylvania high school to develop, implement, and monitor reform efforts that resulted in sustained school turnaround. Semi-structured one-on-one interviews using a qualitative case study approach were used to examine the process of effective school-wide change. Participants' were asked to bring documents and artifacts to their audio recorded interviews for the purpose of triangulating multiple forms of data (Yin, 2009) during the analysis phase. Findings suggest that school turnaround occurred as a result of data driven reform by administrators who served as instructional leaders. The process utilized a backwards-designed approach that allowed for open communication with teachers as well as analysis of formal and informal indicators of progress. Indicators further drove school-wide change, suggesting that change is a continuous process. Conclusions have contributed to research on the educational reform process, applying the theory of change to educational reform, and may assist in implementing change in school districts experiencing low state evaluation scores. [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.]