Summer learning loss is a perennial concern for educators and parents alike. However, researchers have recently questioned whether summer learning loss is just a statistical artifact driven by how achievement is measured across the school year. In this study, we empirically investigated a plausible critique of summer learning loss research, namely that students do not put forth their best effort on the fall test compared with the spring test. While we cannot conclude based on our findings that students do in fact lose ground during the summer, we did not find evidence that seasonal differences in test effort are a main driver of summer learning patterns estimated with MAP Growth assessments.