The Delta Issue #95

Three Things to Know About NAEP Long-Term Trend

Hi y’all, Jessica here.

Tomorrow, National Center for Education Statistics (NCES) releases the NAEP Long Term Trend results.

If you’ve been following NAEP, you might assume this is more of the same data you’ve seen before. It surprised me when I first learned that Long-Term Trend is its own assessment, one that tests different students, uses a different framework, and gives us a window into student achievement that stretches all the way back to the Ford administration.

While Long-Term Trend will likely echo what the main NAEP showed us—learning declines are still very much with us—this is a different test with a longer memory, and it just might show us something the main NAEP couldn’t.

So before the scores come out tomorrow, here are three things worth knowing about NAEP Long-Term Trend:

1. This is a completely different test.

When most people hear “NAEP,” they’re thinking about the Nation’s Report Card—the one that tests 4th and 8th graders, lets us compare states, and has been our national benchmark since the early 1990s.

Tomorrow’s Long-Term Trend release is not that test. In fact, Long-Term Trend is older than the version of NAEP most of us know. It was built differently and, unlike the main NAEP, has stayed largely the same on purpose.

A few important notes:

Ages, not grades. Long-Term Trend tests 9-, 13-, and 17-year-olds, while the main NAEP tests students in 4th and 8th grade. That may sound like splitting hairs, but it means the assessments are measuring different groups of students and can’t be directly compared.
A different reference point. The main NAEP anchors to the early 1990s, while Long-Term Trend anchors to the 1970s. If you’ve ever heard someone say, “Kids just aren’t what they used to be,” this is one of the few datasets that can actually help us test that claim.
National only. There are no state-by-state results here. This is a national picture only. You can’t look at your state and ask, “How did we do?” But you can ask how today’s 13-year-olds compare to 13-year-olds 50 years ago.
Different design. Long-Term Trend has remained largely unchanged—intentionally so—to preserve the trend line. Main NAEP, by contrast, updates its frameworks over time to reflect changes in what schools are teaching today. Each test is built for a different purpose: main NAEP gives you a current, evolving picture; Long-Term Trend gives you the historical one.

The main takeaway is that these are not interchangeable datasets.

2. The long view is the best view.

Last year, when the main NAEP dropped, we wrote about the importance of looking beyond the scores and zooming out to the bigger picture. A decade of NAEP is far more interesting than a single data point because most of the questions we care about in education—whether students are recovering from the pandemic, whether reading instruction is improving, whether math achievement is declining—can only be answered over time.

Long-Term Trend was built for exactly this kind of looking back. It’s the only dataset we have that shows how American students have performed in reading and math over the last 50-plus years.

That’s a pretty remarkable thing when you stop and think about it. Most education debates are fought over the last test administration, the last school year, or the last governor. This dataset lets us step back and see how American students have changed across generations.

So resist the urge to compare this year’s scores to the last release and call it a story. Look at the decade-long trend. Look at the arc. That’s where you’ll find the clearest clues about what’s actually going on.

3. The honesty gap is NAEP’s superpower.

The Honesty Gap analysis is, in my view, one of the most important uses of NAEP data. The National Center for Education Statistics (NCES) publishes its own version, and the Collaborative for Student Success has long conducted its own analysis as well. Both compare the percentage of students states report as proficient on their own assessments with the percentage who reach proficiency on NAEP, providing a clearer picture of how state expectations align with a common national benchmark.

The results can be eye-opening. In the most recent analysis, 42 states had a double-digit gap between what their state assessment reported and what NAEP found. In Alabama, for example, 58 percent of 4th graders were reported proficient in reading on the state assessment. NAEP put the figure at 28 percent—a difference of 30 percentage points.

States have a political incentive to make their numbers look good (happy parents, happy voters). The Honesty Gap analysis provides an important accountability check by showing, in black and white, where state results and NAEP results tell very different stories, and just how large those gaps really are.

The National Center for Education Statistics is working on an updated version using the latest NAEP data, and we’re eager to see it. When those results come out, take a look at how your state’s results compare to NAEP. If the two are moving in different directions, that’s a good moment to ask some hard questions about whether your assessment system is giving families an honest picture of student performance.