The Evidence Behind Common Core Is Really Weak

by Jason Richwine

The Common Core education standards are a massive effort intended to raise educational standards across the country. Untold hours and dollars have already been spent on their implementation, which is still proceeding in more than 40 states even as a few have dropped out. But what is the evidence that the new standards will improve learning?

As I noted a year ago, simple correlations of test scores with standards across states or nations are not definitive, given all of the intervening variables involved in those comparisons.

Now the Center for Education Policy at George Washington University has put together a compendium summarizing over 60 research papers related to Common Core design and implementation. If there is empirical evidence on the importance of strong standards, this is probably the place to find it. Unfortunately, only two papers in the entire compendium are devoted to measuring the impact of Common Core on test scores. Both papers employ the dubious correlation-across-states methodology, and both give mixed results at best.

The first paper, by two Michigan State professors, examines the relationship between states’ math scores in 2009 and the similarity of their math standards (pre–Common Core) to the Common Core math standards. The authors initially find no correlation in the 50-state universe. They are able to detect a positive relationship only with an ex post division of states into two separate groups, with the smaller group consisting of 13 states with low scores despite strong standards. The authors acknowledge that “these analyses should be viewed only as exploratory in nature, merely suggesting the possibility of a relationship.”

The second paper, published by Brookings, follows up on the Michigan State analysis. It finds that states’ test score gains between 2009 and 2012 show no relationship to the similarity of their standards to Common Core. There was no positive correlation even when using the favorable groupings from the Michigan State paper. The one encouraging finding in the Brookings paper is that states with stronger implementation of Common Core seem to show greater gains. But the author warns that, even if the correlation is genuine, the effect size is tiny.

And that’s it.

Much like the push for government preschool, the Common Core movement is suffused with much hope but little evidence. That’s clear from how the standards were developed in the first place. As an important article from last November’s American Journal of Education points out, most of the research evidence behind Common Core focuses on identifying problems — America’s poor international ranking, achievement gaps, high school graduates without basic skills, etc. But when it came to writing standards to address those problems, the Common Core developers had little to go on except the standards of high-performing nations and the “professional judgment” of various stakeholders.

So although the rise of national standards is one of the most significant education policy changes in a generation, and despite the passion of proponents, the data can tell us very little about Common Core’s future impact.

Of course, this isn’t usually the rationale articulated against Common Core — parents’ groups and anti-ed-reform groups have put forth more specific criticisms of the standards and the related testing regimes. But Common Core definitely is ailing: A new poll commissioned by Education Next finds that support for the standards has been slipping nationwide.

The Agenda

NRO’s domestic-policy blog, by Reihan Salam.