PHILADELPHIA » Amy Clipston had a request that was a new one for her daughter’s first-grade teacher.

Many parents had marched in to demand that their children, even those who couldn’t tie their shoes yet, get more homework. Clipston was the first to request the opposite — that her daughter opt out of homework altogether.

“I felt my child was doing quite fine in school,” said Clipston, a chemist with three children, noting that her daughter’s schoolday in the highly competitive Lower Merion School District was 6 1/2 hours, with a 20-minute recess. “I felt 10 to 20 minutes of homework a night was not accomplishing anything.”

Her request, which the teacher approved, represented one small step for a movement slowly gaining momentum in schools around the country: questioning, scaling back or, in a handful of schools, even eliminating the nightly homework ritual once thought as all-American as junior proms and cafeteria food fights.

For decades, homework’s value has been hotly debated.

But now a growing legion of critics say the notion that America can close the learning gap with China or India by stuffing kids’ backpacks with math worksheets as early as kindergarten is backfiring — creating a nation of stressed-out, sleep-deprived children, despite scant scientific evidence they are actually learning more from the reams of homework.

Some school administrators are starting to listen. Radnor School District has unveiled a policy stating that homework shouldn’t “interfere with the student’s health and wellbeing.”

Several New Jersey districts, including Princeton Public Schools and the West Windsor-Plainsboro School District, are experimenting with banning take-home assignments on designated nights or weekends and school vacations.

An elementary school in Gaithersburg, Md., has banned homework altogether in favor of 30 minutes of nightly reading. And under the radar, parents such as Clipston — she says there are others in Lower Merion — are quietly opting their kids out of the daily grind.

That is all music to the ears of Vicki Abeles, who triggered widespread debate on test and homework pressure with her 2010 documentary “Race to Nowhere,” and is back with another film and book, “Beyond Measure,” to look at schools that are breaking the mold. She said educators should be seeking work-life balance for students just as some high-tech companies are doing for employees.

“A lot has been written about adults having real time off from the workday, and that it improves creativity and productivity,” Abeles said. “We’re doing the exact opposite with kids. It’s insanity.”

The anecdotal complaints from parents and teachers about the harmful impact of students emailing completed assignments at 3 a.m. or kids spending sunny weekend days inside on a laptop are increasingly supported by scientific research. The 2013 American Psychological Association survey, for example, found that 45 percent of U.S. schoolchildren were stressed-out by school — and homework was the leading cause.

Many schools try to stick to 10 minutes for each grade level, but some, particularly private ones, load on a lot more. For example, St. Joseph School in Downingtown has a policy of starting with 30 minutes for first and second grade up to 120 minutes for seventh and eighth grade.

“The kids are overwhelmed,” said Tom Di Giulio, a Latin teacher at Cedarbrook Middle School in Cheltenham. “It’s too much. I’m getting work sent in to me at 12 o’clock at night,” sometimes 1 and 3 a.m.

Zach Masterman, 15, a sophomore at Lower Merion’s Harriton, knows what Di Giulio is talking about. After putting in a full day of school, after-school activities and choir practice, he comes home and dives into three hours of homework nightly. “I’m really busy,” he said. “I have a ton of things to do.”

While high schoolers are expected to hit the books every night, Stephanie Brant, the Gaithersburg principal, said she was surprised when she initially got pushback from some parents when she eliminated homework.

They were worried, she said, that their kids wouldn’t be prepared for middle school. But now, not only have other schools in her district jettisoned the worksheets, a middle school principal also thanked her for sending him devoted readers.

“We demand so much of our students during the day,” said Brant. “You can often be doing homework that is rote — addition or whatever — and the second you do one wrong problem, you’re doing 25 wrong.”

But conventions are hard to break. Cathy Hall, assistant head of school at elite Episcopal Academy, said teachers there are keenly aware of the “homework dilemma” and are being “intentional” in what they assign students. Yet at a school that boasts of its Ivy League admissions, time spent on homework is ultimately a personal decision, she said.

And in Lower Merion, opting out of homework — even with a teacher’s blessing — is “a violation of policy,” said spokesman Doug Young. “Homework is part of the school experience.”

It doesn’t have to be, say some critics.

Alfie Kohn, who wrote “The Homework Myth: Why Our Kids Get Too Much of a Bad Thing” a decade ago, said that numerous studies fail to find any link to improved learning.

“There’s really dubious academic benefit to homework at any age, especially in younger kids,” Kohn argued.

What’s more, he and Abeles argue, too much homework can cause considerable harm, raising levels of frustration, anxiety and family tension while robbing time for imaginative play and outdoor exercise, and — most importantly — crushing the potential to get excited about learning.

More parents are asking the same questions. “Many feel homework has kind of taken over, especially at the high school level,” said Cheryl Masterman, Zach’s mother. “I just had a situation with my fifth-grader the other night, and he was up really late and totally freaking out and melting down.”

Anne Heffron, principal of Merion Elementary in Lower Merion, explained: “We’re trying to build habits with kids, and get children into a pattern of being independent, taking responsibility and developing organizational skills.”

Heffron said she gets mixed reactions from parents on the homework issue: Some want more, some less, and some are bothered when they see their child struggle with an assignment. “I think sometimes homework is a bigger stressor for parents than for the kids,” she said.

But Abeles said it’s the stress on kids that concerns her the most. She said she was inspired to launch “Race to Nowhere” after school pressures were blamed for the suicide of a 13-year-old California girl.

Abeles noted that she opted her son out of homework in elementary and middle school, and now he’s doing well with his high school assignments.

“How many hours a day can they be spending on academics?” Abeles asked. “They need to develop in other ways. They need time with families and friends. They need time to do nothing.”