Cal Poly Pomona, in partnership with Pomona Unified School District and Ontario Montclair School District, is preparing 20 middle school Master teachers using a five-year video-based analysis-of-practice professional development program focused on improving Master teacher science and mathematics content knowledge, pedagogical content knowledge and leadership skills. Video and computer technologies provide an opportunity for creating a practice-based program which includes videotaped lessons and coaching sessions with student teachers along with accompanying lesson plans, student work, student assessments and curriculum materials that support important Master teacher learning. The project is looking at program effectiveness in terms of its impact on student teacher learning and retention in the field. A quasi-experimental two-group design allows for comparisons between student teachers whose Cooperating Teacher experienced the CPP MTF program and student teachers who received support from Cooperating Teachers who were not in the program. Pre-post assessments of MTFs' content knowledge, pedagogical content knowledge (PCK), communication and facilitation skills, pre-post videos of MTFs' classroom practice, and pre-post student teacher content knowledge and PCK as well as a longitudinal data base provide the necessary data to analyze factors that predict student teacher learning and their longevity in the teaching profession. The project is using a longitudinal database to track attrition rates of student teachers from both groups to determine the value added to student teachers as a result of their Master teacher's participation in the CPP MTF program. MTFs gain the knowledge and skills necessary to become adjunct faculty in the College of Education and Integrative Studies at Cal Poly Pomona as well as receive state certification as a Teacher Performance Assessment Scorer. Options to become National Board Certified, potential mentors in the Beginning Teacher Support and Assessment (BTSA) Program within their school district or complete the requirements for certification in an additional content field are available to the MTFs. The Huntington Library, located in Pasadena, provides expertise and resources critical to botany content.