Technology in the classroom has become so ubiquitous that the use of papers and pencils or pens seems innovative.

The Wall Street Journal published a front-page story about the high-powered push to buy technology and the growing disillusionment of some parents and teachers.

When Baltimore County, Md., public schools began going digital five years ago, textbooks disappeared from classrooms and paper and pencils were no longer encouraged. All students from kindergarten to 12th grade would eventually get a laptop, helping the district reach the “one-to-one” ratio of one for each child that has become coveted around the country. Teaching apps and digital courses took the place of flashcards and notebooks.

Despite the investment, academic results have mostly slipped in the district of about 115,000 students.

Over the last decade, American schools embraced technology, spending millions of dollars on devices and apps, believing its disruptive power would help many children learn faster, stay in school and be more prepared for a competitive economy. Now many parents and teachers are starting to wonder if all the disruption was a good idea.

Technology has made it easier for students and teachers to communicate and collaborate. It engages many students and allows them to learn at their own pace. But early indications are that tech isn’t a panacea for education. Researchers at Rand Corp. and elsewhere say there is no clear evidence showing which new tech-related education offerings or approaches work in schools.

The uncertainty is feeding alarm among some parents already worried about the amount of time their children spend attached to digital devices. Some believe technology is not doing much to help their kids learn, setting up a clash with tech advocates who say technology is the future of education.

Across the country—in Boston, Fort Wayne, Ind., and Austin, Texas—parents are demanding proof technology works as an educational tool, and insisting on limits. They’re pushing schools to offer low- or screen-free classrooms, picketing board meetings to protest all the online classes and demanding more information about what data is collected on students.

In April, a report from the National Education Policy Center, a nonpartisan research group at the University of Colorado at Boulder, found the rapid adoption of the mostly proprietary technology in education to be rife with “questionable educational assumptions . . . self-interested advocacy by the technology industry, serious threats to student privacy and a lack of research support…”

Baltimore County said earlier this year it would scale back the ratio of laptops in first and second grades to one for every five students. A few miles away, in Montgomery County, a new curriculum this fall will return textbooks, paper and pencils to the classroom to supplement laptops.

In both cases, school officials say they were responding, in part, to parents and teachers. Baltimore County’s early-learning teachers said they didn’t need so many laptops. Parents wanted their children to “have a mixed media experience touching paper and reading books and down on the carpet without a device in their hands,” said Ryan Imbriale, who heads the school district’s department of innovative learning