The recent policy focus on the turnaround of persistently low-achieving schools has generated considerable debate about the reforms needed to dramatically and quickly increase school performance. The purpose of this article is not to focus on specific turnaround interventions, but rather on the identification of schools slated to receive these interventions. Results from the study of 1,059 public schools suggested that operational definitions that relied on No Child Left Behind Act of 2001 metrics overidentified high schools educating diverse populations.