The literature on teacher preparation programs in the United States is extensive. However, there is limited scientifically based research on what kind of program produces effective teachers; rather, the literature consists mostly of calls for change in teacher preparation programs. Almost all experts agree that major changes are needed in these programs, with the emphasis being to produce teachers who are effective in enhancing student learning. This paper reports evidence-based research and offers suggestions based on studies that include theoretical work, qualitative analysis, statistical analysis, and randomized experience that could provide strong causal evidence of the effects of teacher preparation on student learning. Key points of this briefing paper include the following: (1) Relevant clinical experience is a critical part of a teacher preparation program; (2) Programs must take advantage of existing technology and support its innovative use as a tool for teacher preparation and as a tool for teachers in the classroom; and (3) Multiple sources of data should be collected and analyzed to evaluate the effectiveness of preparation programs.