In Pennsylvania, Act 82 of 2012 introduced the Educator Effectiveness system and its foundational belief that student achievement is the result of teachers' high quality instruction and principals' high quality school leadership. With the heightened expectations of principal and teacher accountability for student achievement, principals positively impact student achievement through the day-to-day work of teachers. Principals intentionally design and communicate formative feedback so that teachers learn and grow. This study explored the current practices and beliefs of principals who provide formative feedback to teachers. Principals and assistant principals were surveyed to gather evidence of their self-reported use of effective formative feedback qualities. They were asked to rank order research-based highly effective formative feedback qualities in order of perceived value in leading to teacher learning. Next, seven principals were interviewed regarding the methods they use to provide formative feedback to teachers. The principals were chosen to be interviewed because they reported similar feedback beliefs and practices as those reported in the literature on formative feedback. This study found that principals and assistant principals value different qualities than the ones they use in their daily feedback practices. Additionally, principals and assistant principals believe that certain feedback qualities have an impact on teachers' practices that are different from those supported in the literature as being effective and are also different from those that they use in their own feedback messages to teachers. Principals who report beliefs that reflect the research on formative feedback are better able to defend and explain their feedback practices. When principals intentionally incorporate highly effective formative feedback qualities in their feedback messages to teachers, they contribute to the professional learning of teachers. They also learn and grow themselves, sustaining a professional learning culture. [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.]