One of the main policy responses to turnover and inadequate preparation among beginning teachers is supporting them with an induction program. Informal or low-intensity teacher induction programs are prevalent and include pairing each new teacher with another full-time teacher without providing training, supplemental materials, or release time for the induction. Much less common is induction that is intensive, comprehensive, structured, and delivered sequentially in response to a teacher's emerging pedagogical needs. But there is little evidence on whether investing more resources in a more comprehensive, and more expensive, induction program would help districts attract, develop, and retain beginning teachers. This study examines whether comprehensive teacher induction programs lead to higher teacher retention rates and to other positive teacher and student outcomes compared with the prevailing, generally less comprehensive approaches to supporting new teachers. After the first year, comprehensive induction made a difference only in the support received by beginning teachers. It had no impact on teacher practices, student test scores, teacher retention, or the characteristics of a district's teaching force. (Contains 2 notes.) [For the full report, "Impacts of Comprehensive Teacher Induction: Results from the First Year of a Randomized Controlled Study. NCEE 2009-4034," see ED503061.]