One of the US Department of Education's key priorities is turning around the nation's persistently low-achieving schools, yet exactly how to identify low-performing schools is a task left to state policy makers, and a myriad of definitions have been utilized. In addition, exactly how to recognize when a school begins to turn around is not well established in the research literature. This article presents some of the lessons learned from a project that empirically identified chronically low-performing and turnaround schools in 3 states, and maps out the decision-making process involved in identifying these schools based on performance. (Contains 3 figures, 2 tables, and 21 footnotes.)