This report describes in detail how researchers, policymakers, and program administrators can recognize opportunities for experiments and carry them out. Specifically, the report focuses on opportunistic experiments, defined as randomized controlled trials (RCTs) that study the effects of initiatives, program changes, or policy actions that agencies or programs plan or intend to implement -- as opposed to studying an intervention or policy action that is developed and implemented specifically for a research study. [This report was adapted from "Recognizing and Conducting Opportunistic Experiments in Education: A Guide for Policymakers and Researchers. REL 2014-037" (ED544801).]