The purpose of this study was to examine professional learning practices of school districts that have included choice and differentiation in their approaches to professional learning, and to examine the impact educational leaders' knowledge of andragogy, or adult learning theory, may have had on program development. Andragogy is often ill-defined by educational leaders, and the needs of adult learners are often confused with those of children. While andragogy includes pedagogical approaches to teaching, pedagogy excludes andragogy from its practice. Therefore, it is extremely important to focus on adults' learning needs when attempting to improve teaching practices. This study was qualitative, inductive, and followed critical grounded theory methods. As such, my study refined my worldview and dedication to the practice of continuous improvement. I interviewed eight educational leaders employed in four California school districts using snowball sampling. Leaders were questioned about their beliefs about leadership, the types of professional learning activities available to teachers in their district, how they are demonstrating a commitment to teacher choice and differentiation, and how their understanding of adult learning needs impacts their development of professional learning programs. Leaders also submitted documents that supported professional learning offerings in their districts. Findings from this study indicate a wide variability in leadership beliefs and district practices, largely due to the open-ended nature of the interview questions. Among important findings, the study identified the need for alignment between professional learning practices and district vision, as well as centering program development around learners' needs. Choice and differentiation were recognized as important elements for effective professional learning, as was applicability and relevance to teachers. Through careful review of various types of professional learning offered, five examples were found to be aligned with andragogy and the needs of adult learners: these included inquiry-based learning, action research, learning labs, coaching, and individualized learning plans. While neither definitive nor all-encompassing, inclusion of these types of professional learning would offer teachers increased opportunities to transform their teaching practice and increase student success. [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.]