NAEP, also known as the Nation's Report Card, tests students in both grades every two years on math and reading ability. This year, math scores reversed a long, upward trend with both grades testing lower than they did in 2013.
In 22 states, eighth-grade math scores declined. Overall, 67 percent of eighth-graders are not considered "proficient" in math. For fourth-graders, it's 60 percent.
Reading scores weren't much better. Eighth-grade scores declined from 2013, while fourth-grade reading scores were mostly stagnant. Results from urban areas underscore stubbornly persistent economic and racial achievement gaps.
Education officials admit they're disappointed and a little surprised. What's going on?
Morgan Polikoff, an education professor at the University of Southern California, cautions that the drops should be seen in the context of 25 years of rising scores.
"They are a little bit surprising and certainly troubling and something folks need to think about," says Polikoff. "But I don't think we need to put too much stock in one year's test results giventhe tremendous progress that's been made over the years."
Analysts are already pointing to a range of possible factors behind the dip, including the adoption in more than 40 states of the new Common Core standards for math and English. In many districts, that has changed what and how math is taught. Dan McGrath, an assessment branch chief with the National Center for Education Statistics, says the biggest math dips for fourth-graders were on questions about statistics, data analysis and geometry, which are not part of Common Core guidelines for that grade until late in the year.
Others suggest the social and economic upheaval of the Great Recession may have had a big impact on learning, especially for eighth-graders.
In a conference call with reporters, Education Secretary Arne Duncan noted the changes roiling education nationally: school districts with higher numbers of low-income families, more students who qualify as English language learners, and in some states, the inclusion of children with special needs in the tests.
Duncan also said the sweeping curriculum changes in states adopting Common Core were bound to have an impact on tests.
"I've said on a number of occasions that we should expect scores in this period to bounce around some," Duncan said. He added, "this is really hard work, and big change never happens overnight. And, as the President recently said, 'This is a decades-long or longer proposition.' "
The advocacy group FairTest says the NAEP scores again highlight the nation's unhealthy reliance on standardized testing to boost achievement. "Promoters of 'No Child Left Behind' and similar test-driven schemes in many states promised significant gains in overall academic achievement. They also said historic performance gaps between racial groups would narrow. According to NAEP, neither desirable result has materialized," says FairTest's Bob Schaeffer.
Secretary Duncan told reporters, anyone who thinks he knows exactly why scores are down is peddling a personal agenda, not an educational one.
Some of that is political cover from the soon-departing education secretary who has come under withering criticism from Common Core opponents across the political spectrum. But Polikoff, who studies assessment and accountability, says Duncan has a point. Researchers need time to drill down into the data.
"For every bogus claim, there's an equally bogus counter claim," says Polikoff. "Unless we get good research on this, you can't really extrapolate from one year's test score changes to, you know, indictments of whole policies."
Urban Institute researcher Matthew Chingos argues in a recent report that demographic shifts are key to understanding differences in NAEP scores across states. State to state comparisons, he says, are often misleading because demographic differences create such diverse populations of students.
One example comes from Texas and Oregon. The limited English proficient kids in Texas scored better on the fourth-grade reading test in 2013 than same-grade limited English proficient kids in Oregon. The other students scored about the same in each state. "But Texas has a lot more limited English proficient kids than Oregon and those kids tend to score lower. So Texas's raw score looks worse than Oregon, but it's adjusted score looks better," Chingos says.
Researchers, he says, need "to break the data out and look at a rich set of characteristics and compare how kids are doing in a given state to similar kids around the country, rather than just looking at the average scores."
Polikoff notes that more detailed student-level data from these tests will be released in the coming months. Those scores are a traditionally rich source for education researchers, he says, but one that will take time to unpack.