The criteria for determining the student outcomes that define a school as having "turned around" are not well defined, and the definition of turnaround performance varies across studies. Although current policy initiatives offer guidelines for identifying CLP schools, there is no standard definition or methodology in common usage. This paper summarizes the lessons learned from this exercise of empirically identifying CLP schools and binning them into performance categories based on their trajectories. This paper provides guidance for others charged with a similar task. Specifically, the authors learned the critical importance of using student-level data (rather than school-level aggregate measures), using growth-based measures in conjunction with status-based performance metrics, the stability of these performance metrics over time, and how to empirically recognize turnaround in schools as it occurs. Also, the authors learned that low-performing schools turned around their performance more frequently than one might have presumed based on prior research. In Florida, they identified approximately 15% of chronically low-performing elementary and 14% of chronically low-performing middle schools as turnarounds. Similar rates were observed in North Carolina--13% and 16%, respectively; and even higher in Texas--29% and 31%, respectively. (Contains 3 figures and 2 tables.)