The purpose of this study was to examine the perceptions of principals who have met Adequate Yearly Progress (AYP) with the special education subgroup. This was a qualitative study, utilizing interviews to answer the research questions. The first three research questions analyzed the areas of assessment, building-level leadership, and curriculum and instruction. The results indicated that formative assessments, administered with appropriate accommodations, were critical to guide interventions, instruction, and gauge success. Creating a culture of shared responsibility and accountability for all students was paramount. Designated time had to be built into the master schedule for meaningful collaboration among colleagues, with an intentional focus on data. Layered intervention systems were at the center of increasing student achievement, with a direct connection to ongoing professional development for teachers. The fourth research question looked at the decision making processes and evaluation methods utilized. The results indicated that data drove the decision-making processes and evaluation systems. The fifth research question explored the challenges that principals encountered, and the mistakes they made when making decisions to increase performance outcomes for special education students. Each school had unique needs, precipitating different challenges. Similar to the variance in challenges encountered, there was inconsistency in the mistakes that the principals cited. Recommendations for future research include site visits and observations to the studied local education agencies, focusing on the perceptions of educators within the system, exploring and addressing other state accountability systems, and studying other subgroups. [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.]