Adolescents tend to be a sleep-deprived bunch. I know I was when I was in high school. Adolescents tend to stay up late, in part because of a biological shift in circadian rhythm. Plus, high school starts earliest, which deprives adolescents of sleep as well. On the weekends, some adolescents try to make up for lost sleep by sleeping in, but this does not erase 5 days of partial sleep deprivation. Advocates have requested later school start times to help, but this is not done in most schools.
This study is about kids that are homeschooled. In this population, these kids can sleep in later, offsetting the daytime sleepiness from sleep deprivation as seen in public / private school kids. Also, kids that are homeschooled have a parent with them more often and thus may have better sleep hygiene than public / private school kids - meaning less TV / screen time in bed, less caffeine in evening, etc.
Study participants were surveyed about their sleep patterns and sleep hygiene via internet. Mean age of the sample was 13.6 years old. The results showed that kids in public / private school went to bed somewhat earlier on weekdays, but got up much earlier, resulting in 49 less minutes of sleep than homeschooled kids. Also, public/private school kids tended to sleep in more on weekends than homeschooled children. Using the National Sleep Foundation’s categories of “optimal sleep” (>9 hours) 28.2% of public/private school students obtained optimal sleep on weekday nights compared to 58.0% of homeschooled students. Public/private school kids tended to have "poorer" sleep hygiene than homeschooled kids.
The authors concluded that later school start times would allow private / public school kids to get more sleep.