Recent legislation and accountability efforts in K-12 schools have increased the need to support and maintain high-quality teachers through enhanced professional development and teacher training efforts. As districts and schools seek new and innovative ways to provide professional learning opportunities that are real-time and effective, investments in job-embedded professional development models can support teaching and learning in a world of accountability and federal mandates. This qualitative study explores the experiences and perceptions of professional development facilitators (PDFs) implementing job-embedded professional learning in middle and K-8 schools. The study also examines how well professional development practitioners align program design with the actual implementation of school duties; and it also provides insight into the dynamics, influences, and characteristics of providing on-the-job training in schools to educators real-time and at the point of instructional delivery. Study results are designed to inform districts and schools on the successes, challenges, and program structures needed to effectively design job-embedded activities that yield increases in teacher quality and ultimately student achievement. [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.]