NPR (7/15, O'Connor) reports schools across the state of Florida are debating the appropriate time to start high school courses in the morning. New research from University of Minnesota researcher Kyla Wahlstrom says that high-schoolers go through a sleep phase shift that causes them to naturally go to sleep later in the night and stay asleep longer into the morning. Central Florida school districts are considering changing their schedules based on the new information. St. Johns County Schools decided to start at 9:15 beginning in 2006 and has seen an improvement in student performance since that time.