The report of the American Educational Research Association (AERA) Panel on Research and Teacher Education recommended that teacher educators need to systematically and empirically study their own practice. The premise of the report was that teacher educators need to carry out quality research in order to better inform those inside and outside the field of education. The report was timely, as many outside the field of education question the need for teacher preparation programs as well as their effectiveness in preparing highly qualified teachers as defined by the "No Child Left Behind" legislation. In response, teacher preparation programs need to base their work on solid evidence that indicates whether or not teachers are well prepared by their programs and whether they have a positive impact on student achievement. Without question, university-based teacher preparation programs are under assault at a time when the need for good teacher preparation is more important than ever before. In response to the call for more rigorous self-study by the educational research community and the need for high quality teacher preparation programs, the authors empirically studied their own pedagogical practice, the peer feedback process, during two semesters of clinical experiences to examine how that practice affected teacher candidates' professional development. Peer feedback refers to reciprocal teaching in which paired teacher candidates provide assistance to one another as they incorporate new teaching skills, strategies, and approaches to their teaching, while in a P-12 school setting. The process emphasizes giving and receiving feedback in both written and verbal formats. The goal of reflective peer feedback is to promote self-assessment, collaboration, and professional learning. Although peer feedback practices have been studied in the past, the focus has been on the nature of peer feedback at one point in teacher education programs, rather than its impact over time. Therefore, this study examines how the peer feedback practices teacher candidates gave and received affected their professional development during successive clinical experiences. Changes in, as well as the consistency of, teacher candidate comments and survey responses are the focus of this study. (Contains 3 tables.)