Existing research has demonstrated the influence of school leaders on school and student achievement (Hallinger & Bickman, 1996; Leithwood et al., 2019). Simultaneously, the responsibilities placed on school leaders have increased since the passage of NCLB (Husband & Hunt, 2015; Mitani, 2018). Consequently, working conditions are believed to have a larger influence on school leader turnover than salary (Yan, 2020). The passage of ESSA added new robust educator evaluation systems to school leader responsibilities (Remer, 2017). The purpose of this study was to examine school leaders' self-efficacy in providing evaluative feedback and the varied methods through which they provide feedback in relation to evaluation caseload, and to explore how school leaders describe the influence of evaluation caseload on their ability to improve instructional practice. The following research questions were investigated: 1. How do school leaders in Massachusetts rate their self-efficacy in providing evaluative feedback that supports improved instructional practices? 2. How do school leaders in Massachusetts rate their self-efficacy in providing evaluative feedback through varied methods? 3. Is there a significant relationship in school leaders' self-efficacy in providing evaluative feedback and method of feedback by current caseload size? 4. How do school leaders rate their self-efficacy to improve instructional practice under changing caseload conditions? 5. How do school leaders describe the influence of evaluation caseload on their ability to improve instructional practice? This Sequential Explanatory Mixed-Methods study used a census and network sampling method to distribute a questionnaire to all Massachusetts principals (N=1837) and asked them to forward it to other school leaders. Descriptive and comparative statistics were run. Analysis informed the phase two protocol, which utilized a census sample for focus groups. Focus group data were analyzed using Classic Analysis Strategy (Kreuger & Casey, 2015). Findings suggest large evaluation caseloads impede school leaders' ability to improve instructional practice. This study may add to the existing body of research regarding the evolving role of school leaders. Policy makers and district leaders may use the findings from this study to inform structural changes or policy updates that address school leaders' ability to effectively supervise, evaluate, and improve instructional practice. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]