Study links later middle, high school start times to better student achievement
April 15, 2021
• Changes in school start times have a "significant effect" on the amount of sleep and reported grade point averages of students, according to a working paper to be presented at the annual meeting of the American Educational Research Association. The researchers examined eight districts in Minnesota, four of which transitioned to later start times between 2016 and 2019, affecting 38,019 students in grades 5, 8, 9 and 11.
• Findings suggest districts that moved to later start times saw students' GPAs increase by an average of 0.14 points overall, while predicted GPA increases ranged from 0.10 to 0.17 points. Although the effect on GPAs was "small," said coauthor Rik Lamm, a doctoral student at the University of Minnesota, "it is still meaningful for every student whose grades were helped by only the policy decisions of district leaders."
• In addition, the odds of meeting recommended hours of sleep for students — nine or more hours for students in grades 5 and 8, and eight or more hours for students in grades 9 and 11 — in districts with later start times increased by 16%.