This study took place in an urban high school that implemented the data-driven school improvement plan after it received a grade of "F" in 2010. This school experienced significant growth during the next three years and received a letter grade of "C" in 2011, "B" in 2012, and "A" in 2013. I examined the role of the school administrators and teachers in implementing a school improvement plan that utilized a data-based decision-making model as well as strengths and weaknesses of the implementation. I specifically studied the principals' relationship to the teachers, the teachers' relationships to each other, and the teachers' relationships with the students when they were using data to drive the instructional process. I also examined the expectations and processes the administrators established to ensure the appropriate use of data. The qualitative data was collected from teacher learning log meeting agendas and administrator interviews utilizing the data analysis software NVivo as a tool to organize and sort the data. The data-driven decision-making process presented in this study provided examples of teachers and administrators working together to meet the needs of students. The process provided a non-threatening culture where student achievement and educational practices aligned to ensure that student needs were addressed at their individual levels and educational leadership and collaboration thrived among educators. [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.]