In this meta-analysis, I have reviewed published and unpublished research on single-track, year-round education's effect on science and social studies achievement, 2001-2016. Of 30 studies that met inclusion criteria and had data from which an effect size estimate could be calculated, 7 reported science outcomes (18 effect size estimates) or…

While students begin schooling with high engagement levels, these levels begin to drop in the middle years of schooling but appear to recover somewhat in 10th grade, suggesting that the middle years of schooling are an especially vulnerable time in terms of student engagement (Willms et al., 2009). Moreover disengagement is most common in students…