Reviewing the research, Feiman-Nemser identifies distinct shifts in thinking about teacher induction over the last 50 years. Early advocates viewed induction as a temporary bridge designed to provide support to beginning teachers and ease their entry into teaching. Next came an induction model that combines support with ongoing mentoring and professional development designed to help new teachers develop effective practice. Although both of these models produce benefits in terms of teacher retention, Feiman-Nemser advocates a new model (now operating in some schools) that situates new teachers' development within a collaborative professional community and recognizes that all teachers need to learn throughout their careers. (Contains 1 figure.)