Article

Measured Insights, July 2026

MetaMetrics Brain Trust

9 minute read • Jul 20, 2026

The Editor’s Note

It’s the dog days of summer, a time when the sun shines bright, kids run free, and the everyday routines of school are forgotten. But for too many students, summer also represents a slide—and not the kind you find on a playground or at the pool.

Losing reading and math ability over the summer months puts students well behind their peers. And over time, these losses can add up. In elementary school, those most affected by the summer slide can fall 2.5-3 years behind their peers by the time they reach fifth grade. That’s a gap that’s difficult to close. Summer learning programs can help, but only if students attend. Which begs the question—what more can we do?

[Research] Summer Learning Loss Is Not the Same for Every Student

Developed in collaboration with the School of Education at the University of North Carolina at Chapel Hill and Doctoral Student and Graduate Research Assistant, Yuzi Gao, PhD in Education (Culture, Curriculum, and Teacher Education)

Summer learning loss is often described as a familiar pattern: students make academic gains during the school year and then lose some of that progress during the summer. This idea, sometimes called the “summer slide,” has shaped many conversations about achievement gaps, summer school, and out-of-school learning opportunities. But one important question is sometimes less visible: Do students experience summer learning loss in the same way?

In their study titled “School’s Out: The Role of Summers in Understanding Achievement Disparities,” published in the American Educational Research Journal, Atteberry and McEachin revisited a long-standing question in education research: How much do summers contribute to achievement disparities? Rather than focusing only on average summer learning loss or differences by demographic groups, the authors examined the full range of students’ summer learning experiences. They wanted to understand how much students vary in what happens academically during the summer and whether those differences accumulate over time.

Their findings suggest that the answer is no. Rather than following a single pattern, students’ summer learning experiences differ substantially from one another. Summer learning loss is not simply an average decline that affects students evenly. Instead, students’ summer learning patterns vary dramatically. Some students continue to grow, some maintain much of what they learned, and others lose a substantial portion of their school-year progress.

How the Study Was Conducted
To investigate summer learning loss at a large scale, the researchers used NWEA MAP assessment data from 2008 to 2016. The dataset included more than 200 million test scores from nearly 18 million students across thousands of districts in all 50 states. The researchers examined students’ achievement patterns across Grades 1 through 8 in both English language arts and math. The authors compared learning gains during the school year with learning gains or losses during the summer.

The study focused on four main questions:

How do students’ school-year learning gains, on average, compare with their summer gains or losses?
How much do students vary in what they gain or lose during the summer?
Do the same students tend to lose ground across multiple summers?
How much do summers contribute to students’ end-of-school achievement disparities?

By using a longitudinal growth modeling approach, the authors were able to look beyond a single summer and examine how seasonal learning patterns unfold across multiple years of schooling.

What the Study Found
Atteberry and McEachin found that students, on average, do lose ground during the summer. However, the most important finding is not simply that summer learning loss exists. The more important finding is that summer learning loss varies widely across students.

Some students maintained or even continued to make academic progress during the summer, while others lost nearly as much ground as they had gained during the previous school year. This means that the “average” summer learning pattern does not describe many students very well.

To illustrate how much summer alone can shape achievement, the authors ran a thought experiment: if every student had identical school-year learning gains, with all differences in outcomes arising purely from summer variability, students would still end eighth grade spread across roughly 2.5 standard deviations in test scores. This illustrates that differences in summer learning alone could produce substantial differences in students’ later achievement, even if school-year learning were identical.

The authors also found that summer losses were not randomly distributed. Students who lost ground during one summer were more likely to lose ground again during later summers. In English language arts, more than half of students in one analysis lost ground across five consecutive summers. For these students, summer learning loss was not a one-time setback. It became a repeated pattern.

This accumulation matters. Across several years, repeated summer losses can substantially affect where students end up in the achievement distribution. The authors estimated that among students who experienced losses in all five consecutive summers, those losses amounted to about 39% of their total school-year ELA gains over that period.

Taken together, these findings suggest that summer learning loss is more complex than a single average decline. The issue is not only that students lose some academic skills during the summer. It is also that some students experience repeated and substantial summer setbacks, while others do not. Over time, those differences can contribute meaningfully to achievement disparities.

Implications for Educators
Atteberry and McEachin’s findings suggest that summer should be understood as a critical period for educational equity. The summer months are not simply a break from schooling; they are a time when students’ access to academic, social, and enrichment opportunities can differ widely.

For educators and school leaders, this means that summer learning supports should be planned with attention to students who may experience repeated summer setbacks. These supports may include:

Accessible summer reading and learning programs
Opportunities for students to engage with books and knowledge building activities
Partnerships with libraries, community organizations, and families
Targeted support for students who show repeated summer declines
Attention to attendance, engagement, and program quality

At the same time, this study does not identify one specific program that prevents summer learning loss. Instead, it provides a strong rationale for why summer learning opportunities matter and why they should be sustained, targeted, and carefully studied.

Importantly, these findings are consistent with earlier experimental evidence showing that targeted summer supports can benefit students who are most at risk of losing ground. Kim’s (2006) randomized field trial gave fourth-grade students eight free books to read over summer vacation and encouraged them to practice oral reading with a family member. The intervention produced small but meaningful reading gains overall, with the largest effects concentrated among Black students, Latino students, less fluent readers, and students with fewer books at home. Atteberry and McEachin’s study provides a broader and more recent explanation of why such targeted efforts matter: summer is a period when students’ learning trajectories can diverge in meaningful ways, and interventions like Kim’s suggest that relatively low-cost supports may help reduce those setbacks for the students most at risk of losing ground.

Together, these studies suggest that summer learning loss is both an academic and equity issue. Supporting students during the summer is not only about preventing short-term skill loss. It is also about reducing the repeated learning setbacks that can shape students’ long-term achievement.

Relevance for the Lexile® and Quantile® Frameworks
These studies reinforce the importance of helping students remain engaged in learning during the summer months. The Lexile® Framework for Reading and the Quantile® Framework for Mathematics can support this goal by helping educators, families, and students identify reading materials and mathematical resources that are appropriately matched to students’ abilities. Such information can help guide independent learning and practice during the summer, when students’ learning experiences often differ substantially.

Although neither study evaluated the Lexile® or Quantile® Frameworks directly, Kim (2006) used Lexile® measures to match books to students’ reading ability, and the intervention produced the largest benefits for students with weaker reading skills and fewer books at home. Atteberry and McEachin (2021) further showed that summer learning experiences in both reading and mathematics vary considerably across students and can accumulate over time. Together, these findings suggest that providing students with appropriately matched learning resources in reading and mathematics may be one practical strategy for supporting summer learning and helping reduce the accumulation of learning setbacks over time.

References
Atteberry, A., & McEachin, A. (2021). School’s out: The role of summers in understanding achievement disparities. American Educational Research Journal, 58(2), 239–282. https://doi.org/10.3102/0002831220937285

Kim, J. S. (2006). Effects of a voluntary summer reading intervention on reading achievement: Results from a randomized field trial. Educational Evaluation and Policy Analysis, 28(4), 335–355. https://doi.org/10.3102/01623737028004335

Turn the Page and Press Play: What We’re Reading and Listening To

[Article] Summer learning loss: What we know and what we’re learning, NWEA, Megan Kuhfeld and Andrew McEachin, April 23, 2026
“Summer slide” isn’t new. But what remains uncertain is whether this learning loss is a trivial issue or a major educational concern.

[Article] How Much Learning Loss Happens Over the Summer? Stats + Helpful Tips, Mathnasium, May 8, 2026
Math learning takes a bigger hit over the summer than reading, with the average student losing 25-34% of their school-year progress. So how do we prevent the summer math slide?

[Article] Which Subjects Are Most Affected by Summer Learning Loss? A Parent’s Guide, K12, June 9, 2026
Math is the subject most impacted by summer learning loss. The second? Reading and Vocabulary. So what can parents do to protect their child from the summer brain drain?

[Webinar] Prevent the Summer Slide: Supporting Reading and Math All Summer Long (Recording), MetaMetrics, Amy Lau and Jennifer Caudle Williams, May 21, 2026
Preventing summer learning loss in reading and math is possible…with the right tools and strategies.

[Podcast] How to Prevent Summer Learning Loss Without Killing the Fun, The Education Breakdown, June 24, 2025
Kids can lose 1-3 months of learning over the summer, with math taking the biggest hit. What can parents do to help? Hint, board games are a good solution.

Did You Know?

70-78% of elementary students lose math knowledge over the summer

Reading isn’t much better, with 62-73% of students experiencing a loss. And these losses add up for those significantly affected, with elementary students falling 2.5-3 years behind their peers by fifth grade.