In a summary of Making Summer Count by McCombs, Augustine, Schwartz, et. al., they say:
Research has shown that students’ skills and knowledge often deteriorate during the summer months, with low-income students facing the largest losses. Instruction during the summer has the potential to stop these losses and propel students toward higher achievement. A review of the literature on summer learning loss and summer learning programs, coupled with data from ongoing programs offered by districts and private providers across the United States, demonstrates the potential of summer programs to improve achievement as well as the challenges in creating and maintaining such programs.This is the experience of most all of us, I think: we remember coming back to school after summer vacation and finding we had to remember and relearn some of what we had mastered the previous year. We also have to “get back into the swing of school,” which is not only adjusting to the schedule, I think, but also getting our the thinking methods to be more conceptual.
Year long education should be the default: we do not do that in business or in many activities. Some activities are necessarily seasonal because of the weather changes, but most or much of what we do, we do year-round. Can you imagine what it would be like to return to work after taking two and a half months off? We’d have lots of relearning and retraining to do, never mind catching up with the changes that have occurred since we left. Same applies to sports, dancing, singing. I’ve heard the professional ballet dancers who are out a week because of an injury are two weeks behind upon returning!
See also Summer Learning Loss: The Problem and Some Solutions by Harris Cooper, Tips to Keep Learning Hot This Summer by Johanna Sorrentino, Summer Schools Lead to Better Chance of Top University Place, Study Says (The UK Guardian, 17 Jan 2012) by Jeevan Vasagar, Impacts of a Summer Learning Program by Duncan Chaplin and Jeffery Capizzano, Making the Most of Summer School: A Meta-Analytic and Narrative Review, Summer School: Researched-Based Recommendations for Policy Makers (SERVE Policy Brief, July 2001) by Harris Cooper, The Learning Season: The Untapped Power of Summer to Advance Student Achievement by Beth M. Miller, Ph.D. (Executive Summary, June 2007).