In this article in Education Next, Joshua Goodman (Harvard Kennedy School) reports on his study of the impact of Massachusetts no-school days on student achievement. Using data on school closings and standardized test scores, Goodman concludes that individual student absences “sharply reduce student achievement, particularly in math, but school closings appear to have little impact.” He continues: “These findings should not be taken to mean that instructional time does not matter for student learning; the bulk of the evidence suggest it does. A more likely explanation is that schools and teachers are well prepared to deal with the coordinated disruptions caused by snow days – much more so than they are to handle the less-dramatic but more frequent disruptions caused by poor student attendance.”
When just a few students in a class have been absent, teachers have to choose between spending time helping returning absentees catch up, which takes time away from the rest of the class, or letting returning students fend for themselves, which negatively affects their progress. Either way, the class’s achievement takes a hit. A snow day, on the other hand, can be handled by postponing, compressing, or eliminating non-tested material, which is why these lost school days have so little impact on test scores.
“The negative achievement impacts associated with student absences imply that schools and teachers are not well prepared to deal with the more-frequent disruptions caused by poor student attendance,” concludes Goodman. “Schools and teachers may benefit from investing in strategies to compensate for these disruptions, including the use of self-paced learning technologies that shift the classroom model to one in which all students need not learn the same lesson at the same time.”
“In Defense of Snow Days” by Joshua Goodman in Education Next, Summer 2015 (Vol. 15, #3, p. 64-69), http://educationnext.org/defense-snow-days/