Professional development should be linked to fostering best practice and improving student learning (Darling-Hammond, 2009). By providing ongoing opportunities for professional learning that focus on best practice, teachers are more likely to develop the knowledge and skills associated with high-quality teacher instruction and raising student achievement. However, that intended teacher development and improved student learning often did not happen when teachers participate in professional development activities. This study explored how participation in a Professional Learning Community (PLC) that the teachers themselves developed and directed could improve their overall professional development, including how teachers' experience in a self-developed and self-directed PLC could foster their agency and their overall professional growth. The interviews, lesson plans, journal entries, and PLC meeting transcripts illustrated that the PAR project was effective in promoting voice, ownership, and power that to teacher agency. Also, there was evidence from teachers that going through the PAR process helped them improve their 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.]