Throughout the 2016 campaign and since his election victory, Donald Trump has been spinning Americans a bleak yarn of a nation teetering on the brink of collapse. On the campaign trail, he repeatedly insisted that black voters “suffering” under Democratic control had nothing to lose by casting a vote for him. On Inauguration Day, he told of industrial decline and “American carnage.” The president thinks that public schools “deprive” students of knowledge; that inner cities are riddled with crime; that the health care system is about to implode (or perhaps explode); and that the country is losing out big league to allies who’ve been treating Americans like chumps.

But this doomsaying isn’t just coming from the Oval Office. On Wednesday, at a forum at the Brookings Institution in Washington, the president’s Education Secretary Betsy DeVos was asked whether she would concede that when poorly implemented, the “school choice” doctrine she has championed for much of her career could have a negative effect on students. She saw no such risk:

“Well, I’m not sure how they could get a lot worse on, you know, a nationwide basis than they are today,” the secretary said. “The fact that our PISA scores have continued to deteriorate as compared to the rest of the world and, you know, that we’ve seen stagnant—at best—results with the NAEP scores over the years—I’m not sure that we can deteriorate a whole lot.”

American carnage—right in America’s classrooms!

The problem with DeVos’ sweeping assertion—and by extension, her apocalyptic view of American public education—is that the numbers tell a more complex, muddier story. Take PISA, the Programme for International Student Assessment, a test that compares 15-year-olds’ performance across dozens of countries. Depending on how you read the most recent PISA results from 2015, American schools could be described as doing great (we’re ahead of Switzerland in reading, and above France and Sweden in science), as doing OK (the U.S. placed near the middle overall), or as failing miserably (America’s math ranking is bad and has gotten worse since 2012).

And, of course, numbers can also be an unreliable diagnostic tool: Just because you think the PISA or National Assessment of Educational Progress numbers are awful doesn’t mean you know what to do to improve them—or even know how to track that you’re doing something right. DeVos certainly doesn’t seem to: Asked earlier in the Brookings Q&A what dataset could be used to assess her own performance as education secretary in four years’ time, DeVos rambled a little about the primacy of policies that favor choice while conceding, “I’m not a numbers person.”

If the secretary of education were a numbers person, the data and research available might make her reconsider her uncritical embrace of school choice. As Ray Fisman and Michael Luca wrote in Slate in January, DeVos’ big public policy idea—basically, that the private sector and local authorities will always do a better job at education than the big, unwieldy federal government—can’t really be supported. And, as Sarah Carr wrote around the time Democrats and some Republicans were lining up to oppose DeVos’ confirmation as secretary, even proponents of the school choice movement have walked back from some of the more radical under-regulated varieties of charter- and voucher-based models they were lobbying for during the 1990s.

This isn’t to say that DeVos’ favored policy of school choice is always a bad idea—just that it hasn’t always worked in every single place it’s been implemented. In Milwaukee, for example, which was the first American city to implement a voucher system, the logic that parental choice and minimal regulation would create a virtuous cycle of ever-improving schools proved faulty. Instead, the lack of accountability mechanisms contributed to a system in which bad schools thrived—including one run by a convicted rapist, and another run by a businessman who falsified enrollment data to attract students and instead spent the cash on a new Mercedes-Benz.

In Detroit, too, where DeVos has flexed great influence on education policy, the choice doctrine has a very mixed record: As Conor Williams wrote in the Washington Post in January, Detroit’s accountability mechanisms for charter schools are flimsy, and yet that flexibility has failed to boost achievement rates in the city. Plenty of systems that feature a degree of school choice are doing OK, of course; those places also seem to feature a greater degree of regulation of charters.

If DeVos had looked closely at those PISA numbers she takes as evidence of catastrophe, she might have learned how much the states that embrace school choice vary in their outcomes. As the Organisation for Economic Co-operation and Development, which administrates PISA, noted last year, the United States—with its fairly unique system of local control—shows “significant performance variability” between states. At the state level, DeVos’ claim of continued PISA deterioration doesn’t really hold up.

In 2015, in addition to its nationwide assessment, PISA looked specifically at two states—Massachusetts and North Carolina—to produce “reliable state-level results.” Massachusetts did well. In fact, if it were a country, Massachusetts’ students would be among the best in the world: ahead of students in Finland, South Korea, and Japan in reading; Canada and Germany in science; and Sweden and France in math. Comparatively, North Carolina did just OK: about the same as the U.S. overall, and not that impressively compared to rich European and Asian countries. So what do we take from that? That America’s education system—comprising district school boards, state education departments, and DeVos’ own federal Department of Education—is varied and complex, and that its performance nationwide can’t be easily summed up.

One thing Betsy DeVos has been clear on (and it’s a fairly short list) is that in education policy, one size doesn’t fit all—especially in a country as big and varied as the United States. On that point, the secretary is right. But what she seems to miss is that her own one-size-fits-all plan—school choice, everywhere, all the time—has a pretty mixed record. If she did want to become more of a numbers person, Massachusetts—where students are actually pretty good at math—might be a good place to start. Because while education sector numbers are complicated, they’re the best thing we’ve got. And while choice is good, there’s an active role for both state and federal governments in ensuring the education system serves all American students.