When I caught a seventh student in the classroom trying to bury his Chromebook in his crotch, clumsily angling the screen below the desk to hide the networked game he was playing, I wondered whether there’s any evidence that Chromebooks actually help educate schoolchildren.

As it turns out, there is none. No longitudinal studies have shown improved student performance since Chromebooks, iPads, and learning software from Silicon Valley corporations started piling up in U.S. school districts. Standardized test scores, grade point averages, and graduation rates have not risen in any way that can plausibly be linked to education technology, or EdTech.

“I don’t know any well-designed studies that show a positive impact on student performance,” said Leonie Haimson, founder of the New York City non-profit Class Size Matters. “It is generally not in the interest of the EdTech vendors who sell these products to commission independent evaluations of their value.”

EdTech is under fire over misuse of students’ private data, wealth transfers from school districts to large corporations, and health concerns about children subjected to excessive screen time. But among these negative side effects, less attention is paid to the central failure of the industry. It is supposed to be educating students, but most evidence shows it is not. On the contrary, there are reasons to believe these technologies—the manipulation of which often consumes the majority of a student’s day—distract students, drag down their performance, and exacerbate the struggles of poorer schools.

I searched in vain for EdTech’s value proposition after a semester as a substitute in Alexandria, Virginia, which operates an underperforming school system inside the Washington beltway. When I asked around, most full-time teachers in the K-12 system told me they did not believe student performance is improving with the spread of Chromebooks. The teachers spend time using the technology to remotely observe student activity online, and intervene to close students’ internet browser tabs when they stray to videos of YouTube soccer, pop stars like Cardi B, or popular network games like “Shell Shockers.”

The teachers aren’t the only ones watching the kids. Tech giants are using EdTech to collect a galaxy of intimate data on nearly every American student. Google, Apple, and Facebook have records on many or most American students, yet these companies—and their offshoots such as the nonprofit Bill & Melinda Gates Foundation or the limited liability company [Priscilla] Chan [Mark] Zuckerberg Initiative—give no evidence that the products help educate or increase test scores.

Groups like Haimson’s Class Size Matters are leading a backlash against a digital rush that has transformed American schools in the past decade. Parents fear loss of privacy and control over children’s online habits. Individual teachers say students can’t focus. Education experts say there’s no proof EdTech is doing what reasonable observers would presume it should do: help educate children.

“We found little evidence of a positive relationship between student performance on [the Program for International Student Assessment] and their self-reported use of technology, and some evidence of a negative impact,” Paris-based Reboot Foundation said in an extensive report released in June. “Fourth-grade students who reported using tablets in ‘all or almost all’ classes scored 14 points lower on the reading exam than students who reported ‘never’ using classroom tablets. This difference in scores is the equivalent of a full grade level, or a year’s worth of learning.”

If it’s a surprise that any school—let alone a large number of them—not only allows but requires fourth graders to use iPads in “all or almost all” of their classes, you haven’t been in a classroom lately. School districts now pair each kid with a device that they are expected to maintain all year, in what is called a “one-to-one” program. Where teachers once grumbled about kids being distracted by their phones, they now require students to be online for much of the day, despite evidence that this is counterproductive.

“[S]tudents who use computers very frequently at school do a lot worse in most learning outcomes, even after accounting for social background and student demographics,” said a 2015 study of Organization for Economic Cooperation and Development countries. “The results also show no appreciable improvements in student achievement in reading, mathematics or science in the countries that had invested heavily in ICT [information and communications technology] for education.”

In the years since that study, tech giants have increased their share of the education market.

“Forty million students and educators rely on Google Classroom to stay organized and support creative teaching techniques,” Google director for international education John Vamvakitis wrote in January. “Thirty million more use Chromebooks to open up a world of possibilities both inside and outside the classroom.”

More than 66 percent of schools supply tablets or laptops to students, MidAmerica Nazarene University reported in 2018—usually on a “one-to-one” basis. Classrooms are festooned with handwritten signs reminding children (usually in vain) that they must come to class with a fully charged Chromebook.

Meanwhile, outcomes continue to worsen. Citing “overwhelming evidence [of] poor performance of full-time virtual and blended learning schools,” the National Education Policy Center at the University of Colorado called for a nearly complete stop to EdTech infiltration in its May Virtual Schools report. Recommendations included slowing or stopping the expansion of both virtual and “blended” schools; requiring these schools to reduce student-to-teacher ratios; conducting serious research; and sanctioning tech-laden schools that underperform.

“Our test scores have been on a downward trend since Chromebooks came in,” said Brooke Henderson, a Missouri teacher and mother of school-age children. “Who the hell thought we were going to roll out these devices without following up?”

Henderson noted that the Springfield school district, whose “IGNiTE” initiative promised to ensure “equity of access to mobile technology”—including providing every student a tablet or laptop beginning in the 2016-2017 school year—has seen its graduation rates fall relative to other Show Me State districts, while its dropout rate increased.

Silicon Valley is largely silent as the negative data pile up. The Chan Zuckerberg Initiative declined to comment. Google did not respond to queries. A spokesman for the Gates Foundation also declined to comment but pointed to two reports. A 2014 analysis by Columbia University Teachers College showed students in a “Teach to One” math program performing better than the national average. A 2017 RAND Corporation report on “personalized learning” funded by the Gates Foundation also showed substantial improvement for math students in all categories.

These are slim pickings considering that the promise of voluminous, analyzable student data was one of EdTech’s main selling points. If Google has good news to report, its silence is puzzling. The results of the RAND study are mixed enough that some skeptics point to it as evidence against EdTech.

“RAND, even with Gates funding it, is pretty inconclusive,” said Matt Miles, co-author of the 2017 book Screen Schooled. In their book, Miles and Joe Clement, long-time teachers in Northern Virginia, studied tech distraction among students at cognitive, psychological, and educational levels.

“Internationally,” continued Miles, “these programs are not looking very effective. Australia has had declining scores on P.I.S.A. and standardized tests.”

But where phone and game distractions are inevitable hazards of our time, the one-to-one programs are something schools themselves mandate. In many cases, the same people who complain about young people’s attention deficits, who draw blinds in classrooms so students won’t gaze out the window, are forcing first graders to use devices connected to the internet and wondering why they can’t concentrate.

Most districts at the start of this decade limited personal devices to upper grades, but ages of consent keep slipping. It’s now normal for third graders to be expected to keep a one-to-one Chromebook throughout the school year, while students as young as pre-kindergarten use shared classroom devices.

The tech industry has made vast inroads into education since Los Angeles Unified School District launched its scandal-plagued effort to give every kid an iPad in 2013. To get an idea of the scale, consider that 66 percent of schools supply children with devices (cited above), and apply that number to Census Bureau estimates of the K-12 population. This would mean more than 30 million students.

By comparison, Chris Whittle’s Channel One, a television-in-schools initiative that in the late 1990s became the subject of a bipartisan backlash, reached only 13 million students per year. Channel One sparked a national panic over corporate sponsorships and advertising to schoolchildren.

Yet this more radical, extensive, and lucrative takeover of schools by the richest corporations on Earth barely gets noted, while the responsible parties assume the vendors’ motives are benign.

“Technology, computers, and software, are tools, just like textbooks and paintbrushes and cellos in the classroom,” said Valerie Truesdale, assistant executive director of the American Association of School Administrators.

“Teaching is about skillful use of any and all tools available for increasing understanding,” Truesdale said. “Technology can assist with building understanding, or [it can] monopolize time with no real gain in learning.”

While she defended the use of technology in schools, Truesdale concurred that no third-party research exists to suggest academic performance has improved as a result of the one-to-one programs.

Screen Schooled author Clement argued that expensive programs to introduce technology should be discontinued if there’s no evidence of their efficacy. He said:

There’s a double standard on burden of proof. People who are skeptical of spending all this money and forcing these programs on kids are the ones who are dismissed as Luddites and naysayers, who have to prove that there’s a problem. It should be the other way around. If you’re suggesting some radical change to the way education works, the burden of proof should be on you.

“Our whole society has transformed with the expectation that Google and Apple are everywhere, and only in the last year has it begun to sink in that their business model is data collection and advertising,” said Josh Golin, executive director of the Campaign for a Commercial-Free Childhood. “We have teachers every day telling students to google things, and Google is not a verb. It’s a brand.”

Golin credited the current wave of EdTech companies with learning from the mistakes of Channel One, which famously assured investors of its ability to target a captive audience. EdTech sales pitches downplay advertising and data harvesting. Instead of solid promises about improved academic performance, vendors make vague claims about increasing student “engagement.” Golin said:

Educators have bought into this idea of good and bad screen time, that what students do on their phones or at home is bad, but what they’re doing on these devices at school is good. But you’re still giving kids a device with access to the world’s largest collection of porn and the world’s largest video arcade. Look at all the adults who spend too much time on the internet at work. For kids who have not fully developed their impulse control, the problem is just intensified.

While there has lately been pushback, teachers may be “feeding the beast,” said Seth Evans, a retired Massachusetts teacher who also works with the Campaign for a Commercial-Free Childhood. He said:

You turn on the computers and the kids shut up. They quiet down. It’s like parents with rowdy kids. Teachers are susceptible to the same temptations. But then it’s very difficult to get the kids to focus. The last few years I taught, I would look around the class and think, ‘How is this possible, that half the students—two-thirds—seem to have A.D.D.?’ As I started making these observations, I asked other teachers, and they all agreed that managing the class is getting harder.

Such old-fogey lamentations are expected, even welcome, to proponents of “disruptive” technologies geared to “digital native” kids and designed, in the words of one EdTech advocate contacted for this article, to “meet students where they’re at.” But while EdTech can shift blame, it can’t show results.

“There isn’t the extent of research you’re looking for,” said Faith Boninger, an executive at National Education Policy Center. “Why not? Why aren’t we examining these things before spreading them around? If you’re going to require kids to use computer programs in schools, you need to know what they’re really doing.”