Increasing persistence and retention in science, technology, engineering, and mathematics (STEM) is essential for building a highly qualified STEM workforce. This project at Rutgers University will support the development of a rigorous and structured peer leader training program in STEM disciplines: Preparation in STEM Leadership (PSL) Program. The PSL Program will serve as a model for academic support services that moves beyond remedial support to create an environment of scholarship and enrichment. Such a transformation will provide a national model for maximizing the potential of academic support services using similar active, collaborative, and student-centered methods. The complementary development of content knowledge, pedagogical knowledge, and leadership and communication skills at the college level will contribute to a better equipped STEM workforce because these participants will be prepared for leadership positions that involve mentoring, teaching, and training others. In addition, this project will enable the compilation of a set of complementary valid and reliable assessment instruments to measure the cognitive and professional development of peer leaders. The evaluation of the PSL Program will identify specific criteria essential for successful peer leader training, which will serve as standards for programs within and beyond Rutgers. The PSL Program will combine extended training in STEM content, mentoring, communication, leadership, and group facilitation with a 3-credit, 300-level pedagogy course to create a comprehensive professional development program. The PSL Program will be evaluated using a combination of quantitative and qualitative data to measure learning gains in participants' content knowledge and pedagogical content knowledge, changes in student?s attitudes and epistemological beliefs related to learning science, improvement in job performance, and the development of leadership and communication skills.