A Tale of Two Tests

By : Courtney Vahle, Ed.D. and Collin Hitt, Ph.D.

Published On: June 27, 2025

When it comes to student achievement in Missouri, the story depends on which test you’re reading.

Since the COVID-19 pandemic, Missouri students—like students across the country—have faced significant academic challenges. The National Assessment of Educational Progress (NAEP), often referred to as the "Nation’s Report Card," tells us that reading and math scores in Missouri have dropped dramatically for both 4th and 8th graders. But a look at the state’s own MAP (Missouri Assessment Program) test results paints a different picture: only slight declines, and in some cases, no decline at all.

So what’s going on?

The Numbers Don’t Match

Let’s start with what the data says. When using standard deviations to measure change on each test:

• Reading scores on NAEP fell twice as much as MAP scores in both 4th and 8th grade.

• In math, the differences are even more dramatic:

  • In 4th grade, NAEP shows nearly four times the decline as MAP.

  • In 8th grade, NAEP shows the largest math drop of any group tested, while MAP scores remained virtually flat.

Possible Explanations

Here are some plausible reasons behind the mismatch:

1. Different Tests, Different Content

It’s true that NAEP focuses narrowly on reading, while MAP tests the broader umbrella of English Language Arts (ELA). That could account for some variation in a single year. But it doesn’t fully explain the difference in trends over time. If NAEP reading scores are plummeting while ELA remains steady, it might suggest that core reading skills are weakening—even if overall ELA performance looks fine.

In math, the situation is more complex. MAP tests are aligned to Missouri’s standards, while NAEP is not. Plus, more advanced 8th graders are now taking Algebra End-of-Course (EOC) exams instead of the standard 8th grade MAP, changing who’s included in the MAP sample—but not in the NAEP sample. Oddly enough, this shift should have made MAP scores worse, not better.

2. Sampling Differences

MAP tests are administered to nearly all Missouri students, while NAEP tests a sample of about 1,800 per grade and subject. While it’s possible sampling has an impact on the score discrepancies, Missouri’s NAEP trends mirror national trends, which makes random sampling error an unlikely explanation.

3. Tests May Have Quietly Changed

Both tests claim to be comparable over time—but testing isn’t simple. The algorithms that score student performance are complex. A score of 250 in 2019 might not mean the same thing as a 250 in 2024, even if the number is the same.

Why This Matters

If NAEP is right and MAP is missing the decline, then Missouri has a much bigger learning loss problem than state data suggests—and it’s going under-addressed. On the other hand, if NAEP is misrepresenting student performance, corrective action is needed.

Either way, the divergence between these two tests is too big to ignore. Missouri families, educators, and policymakers deserve a clear, honest understanding of how our students are doing. Right now, the signals we’re getting are mixed. If we don’t know where our students are academically, we won’t know how to help them move forward.

Text from this blog post also appears in our Policy Brief, A Tale of Two Tests, found here. To read more about MAP scores, read our full Policy Brief here.

MORE FROM THE PRiME BLOGS