In 2007, the Woodrow Wilson National Fellowship Foundation, with support from the Lehman Brothers Foundation, commissioned Public Agenda to explore interest in teaching careers among high-achieving college students, recent graduates, and potential career changers. MetLife Foundation, specifically interested in potential career changers as teachers, funded the Woodrow Wilson Foundation for two projects to expand this initial research. The first, a review of previous findings on career changers in teaching, is presented in this report. The second, published in a companion volume, is a public opinion survey that aims to gauge interest in teaching among the nation's college-educated adults and to assess what might lead more of them to choose teaching. As a guide to what is already known about career changers and their motivations to teach, this current report combines the findings from Woodrow Wilson's initial Public Agenda focus groups with an independent review of existing research on career changers. Based on this literature review and the new data that accompanies it, the Woodrow Wilson Foundation offers a series of recommendations for policy, research, and teacher preparation. "Encore Performances" offers potential new directions for leaders of teacher preparation programs, as well as policymakers and researchers. It looks at the differences between what is known and what has been said about career changers in teaching. It documents the rise of programs that prepare career changers to teach, and reviews what is known about their impact. It examines the motivations and experiences of career changers in their transitions to teaching, and it offers recommendations to strengthen the programs designed to recruit and prepare them for classroom careers. Characteristics of Programs Offering Alternative Routes to Teacher Certification, by State are appended. A bibliography is included. (Contains 1 figure and 20 footnotes.)