Why Did NAEP Scores Drop?

The recent release of the 2015 NAEP results by the U.S. Department of Education’s National Center for Education Statistics have been labeled “historic” by some because math scores at both Grades 4 and 8 and reading at Grade 8 have all declined.

These are the first declines in math scores since the current NAEP frameworks were put in place in 1990. And in 30 states, students had lower math scores in either or both Grades 4 and 8. Especially at Grade 8, most subgroups—males, females, and minority groups—declined in math or reading.

So what’s different? Why the drop in scores?

No one knows for certain, but before we start pointing fingers at any single cause, let’s look at the declines in more detail and context.  

First, the drops for this current assessment are relatively small—two points (to 240) in Grade 4 math and three points each in Grade 8 math (to 282) and reading (to 265). Reading went up one point in Grade 4 (to 223).

Second, reading scores have dropped twice before, even though they have not changed much year to year in more than 23 years. In 1992, the average Grade 8 reading score was 260. It peaked in 2008, when the score hit 268—a mere eight-point gain over 23 years. The reading gain at Grade 4 is even smaller over those years—six points.

So for reading scores, the 2015 results differ little from what we have seen in previous NAEP releases.  

The drop in NAEP math scores, while also small, requires more analysis—and probably more investigation.

Unlike reading scores, those for math have improved significantly since 1990, when the average Grade 4 score was 213. By 2013, Grade 4 math scores hit a high of 242. That’s an impressive 29-point gain. In the same period, Grade 8 math scores grew from 263 to a high of 285—a 22-point gain.

Given this history of growth, what could have accounted for the drops in 2015? 

One change in the vast majority of states is the adoption of more rigorous standards designed to better prepare our students for college and work, most often the Common Core State Standards (CCSS).

The CCSS—developed in response to the need to get our kids from kindergarten through high school ready for the challenges of rigorous college curricula or good jobs—shouldn’t be the baby that is thrown out with the bathwater. Neither should other college and career readiness standards developed by some states. 

Other factors are at play. While new, locally developed higher standards have been adopted in most states, implementation in many places is still in the early stages. New curricula are being developed and introduced to teachers and students that are far more demanding than the curricula they replaced.

For example, students are now expected to collect evidence and build arguments from that evidence as a way to learn the skills needed for both college and work. And some teachers have not yet been adequately taught how to teach these skills.  

While most states have provided some professional development on how to teach the content associated with their new standards, anecdotal evidence suggests that in most cases there hasn’t been enough training to get teachers fully up to speed. 

But perhaps most important, teachers need time to build hands-on experience with the new standards, and the curricula based on them. It may be years before all teachers are well prepared for their new assignments.

Another possible explanation could be an uneven match between what our students are being taught and what NAEP is measuring. A recent study completed by the NAEP Validity Studies Panel (which the American Institutes for Research convenes for the National Center for Educational Statistics) examined one dimension of this issue.

One of two research questions studied was how well the 2015 NAEP math items at Grades 4 and 8 aligned with the CCSS math standards. (Full disclosure: Besides conducting many years of research on NAEP-related topics, George Bohrnstedt chairs the NAEP Validity Studies Panel. Fran Stancavage is the Panel’s project director and a co-author of the study.)

The panel of 18 math educators, math supervisors and mathematicians found that 79 percent of items at Grade 4 and 87 percent of items at Grade 8 assessed content that would have been taught in classrooms that follow the CCSS, at or below the grade tested by NAEP. In most cases, the “unmatched” content was taught at higher grade levels.

But breaking down the total score on the 2015 NAEP test results into its five math content areas provides a somewhat different picture. Sub-scores for the content area in which the match rate was lowest at both grade levels—“data analysis, statistics, and probability”—dropped four points at Grade 4 and five points at Grade 8. Scores for Grade 4 geometry, another area in which the match rate was low, dropped five points.

NAEP needs to balance both what it has been measuring with what is currently being taught in the nation’s classrooms. Given that the vast majority of states are now implementing some version of college and career standards, NAEP may want to re-examine its frameworks for some possible changes, especially where the NAEP Validity Studies panel found some differences between the content NAEP is testing and what the new standards call for.

There are several possible reasons why NAEP scores may have dropped. And there may well be reasons besides those suggested here. But we can say:

  1. The drops were small.
  2. Curricula based on the more rigorous college and career standards, such as the CCSS, are being unevenly implemented in districts and schools.
  3. There is some evidence that the drop in math may be related to differences between what NAEP is measuring and the content associated with CCSS in math at the grade levels tested.    

We also need better—and more—research. What does the implementation of the new college and career standards look like “on the ground?” And what is the exact relationship of all college and career standards to NAEP? Finally, we need to relate this research to NAEP outcomes in the future to determine if what we witnessed this year was just a one-time blip. 

George Bohrnstedt is senior vice president for research, emeritus, a sociologist, and an AIR Institute Fellow who studies student achievement and other outcomes through analysis of NAEP data. He also chairs the NAEP Validity Studies Panel.

Fran Stancavage is a managing director at AIR. She is a co-author of the 2015 NAEP Validity Studies Report. She is project director of the NAEP Validity Studies Panel.