RALEIGH — In the field of K-12 innovation, the digital device dominates. An increasing number of school districts nationwide are leveraging electronic platforms to deliver educational content to students.

No child is too young for screen-based instruction: Districts in states from Maine to South Carolina to California now give iPads to kindergartners, claiming the tablets boost literacy and technology skills.

As we race toward technology immersion from age 5 on, what will be the impact on students? Will schools churn out unprecedented numbers of 21st-century learners who think critically, collaborate effectively, and perform proficiently on standardized tests? Or will we discover that all of that swiping, scanning, and searching wasn’t real learning after all?

A close look at the evidence ought to dampen our digital ardor.

Most of the truly rigorous research to date addressing digital learning doesn’t even pertain to K-12 students. A 2010 research meta-analysis from the U.S. Department of Education of 1,000-plus studies conducted between 1996 and 2008 found that only five both evaluated K-12 students and were sufficiently rigorous to merit inclusion.

Overall, the meta-analysis makes a strong case for e-learning for older students: Blended instruction (incorporating both face-to-face and online instruction) led to better student outcomes than either approach used exclusively. But these students were drawn almost entirely from higher education or training contexts, causing researchers to urge, “Caution is required in generalizing to the K-12 population.”

How effective are wildly popular one-to-one computing initiatives, in which every student is given a device for in-school and at-home learning? Hard evidence that justifies school districts’ considerable cash outlays for individual student laptops or tablets is scant.

Though participants say the devices ramp up student engagement, motivation, and collaboration, objective data from standardized tests show IT saturation has no consistent positive impact on achievement.

Proponents of one-to-one computing suggest test scores do not reflect the full spectrum of benefits. That may be, but such a claim could be made of virtually any education reform. Let’s be clear: Student achievement as measured by standardized assessments is, and will remain, the holy grail of real reform.

As we evaluate one-to-one initiatives, we also ought to consider the trajectory of child development. While workers and older students clearly need technological competencies, do elementary school kids?

Such skills are remarkably easy to acquire, as psychologist Aric Sigman noted in a 2010 presentation to the European Parliament’s Quality of Childhood Group. Primate research from Tulane University has shown that even monkeys can be trained on computers to solve problems using a touchscreen.

What about the health effects of screen saturation? Research documenting the negative impact of excessive screen time on child health is mounting. A 2012 Japanese study of more than 2,000 elementary and middle school children found that more than three hours daily with IT devices including computers may cause sleep problems.

Still other studies link sustained screen exposure from computers and other devices to attention and behavioral issues. Even among young adults, 2012 research from the University of Gothenburg’s Institute of Medicine in Sweden found an association between high computer use (more than four hours daily) and poorer mental health outcomes.

We conduct a grand experiment when we saturate young children with screens. And for what? Kids don’t perform any better. Obviously, technology has its place in 21st-century classrooms. But there’s no evidence supporting total immersion.

Of districts’ stampede to provide schoolchildren with the latest devices, Stanford University professor emeritus Larry Cuban has written, “The research pantry is nearly empty.” For young children, learning isn’t better with a box.

Kristen Blair is a North Carolina Education Alliance fellow.