Teacher preparation programs have both a desire and a responsibility to demonstrate, with affirmative evidence, that teacher education makes a difference in PreK-12 student learning. Program faculty need good data to make decisions about the progress of students, whom to recommend for state licensure, and how to improve teacher education. This article describes an American Psychological Association task force report that discusses 3 measures of program effectiveness that have potential for both informing the public and providing useful data for programs to continuously improve: (a) outcome data from PreK-12 student academic growth as assessed by standardized tests; (b) teacher performance as evaluated by valid and reliable observational instruments; and (c) judgments of graduates, their PreK-12 students, and those who hire teachers as gauged by surveys. Although no technique of data collection and analysis is perfect, this report provides directions for teacher educators who seek to continuously improve their programs.