Research-practice partnerships often face a fundamental tension: well-designed, high-quality research takes time, but practitioners and policy makers need answers to pressing questions as soon as possible. In this article, Jason Sachs, Meghan McCormick, JoAnn Hsueh, and Catherine Snow discuss this mismatch between the tight timelines of educational decision makers and the typically longer timelines of researchers who are pursuing rigorous analyses. They tell us how, in a partnership between researchers and the Boston Public Schools Department of Early Childhood, they’ve worked to make fast-turnaround research as rigorous as they can, while also conducting longer-term causal studies. Because policy makers and practitioners typically aren’t highly trained in study design and causal inference, a key responsibility for researchers is communicating the strengths and limitations of fast-turnaround work in ways that can be easily understood by their partners— and making it clear that fast-response analyses should be viewed as only one piece of evidence for guiding a decision. (author abstract)