As school doors swing open, it will be time once again to engage the homework battles.

A major front, every year, is the parents' complaint that schools give too much homework. This campaign has received recent reinforcement with the publication of "Teach Your Children Well" by Madeline Levine, a psychologist who treats adolescents in affluent Marin County, Calif. Levine says that high-pressure parenting with Ivy League goals can leave kids feeling empty inside. Family rituals that generate enthusiasm and contentment are being lost.

Canada has gotten this message. The nation's education minister has directed schools to make sure students are not overloaded. Toronto schools, with nearly 300,000 kids, have limited elementary school homework to reading, eliminated holiday homework and adopted language endorsing the value of family time.

U.S. schools are also experimenting with reduced homework, but there is no national directive like in Canada.

The Banks County Middle School in Homer, Ga., stopped assigning regular homework in 2005. Grades are up, and so are results on statewide tests.

The Kino School, a private K-12 school in Tucson, Ariz., allows time for homework during the school day. Kids can get help with the work if they need it, or spend the time socializing and do their homework later. Giving kids this choice teaches them to manage their time.

Not all the experiments are positive, though. In the 2010-2011 school year, the schools in Irving, Texas, stopped counting homework as part of a student's grade. After six weeks, more than half the high school students were failing a class - a huge increase. The kids seem to lack the judgment and experience to know on their own when additional studying or work outside class is needed in order to pass tests and complete projects.

There ought to be a middle ground. Mandating "no homework" days or weekends, or setting guidelines for how much time children should spend on homework according to their age, seems reasonable.

One leading researcher, Harris Cooper at Duke University, recommends 10 minutes of homework a night for each grade a child is in. In other words, 10 minutes in first grade, 30 minutes in third grade, etc. For middle school and high school students, Cooper found no academic gains after one-and-a-half to two hours of homework a night.

Couldn't teachers assign homework only when the work really can't be accomplished in school? Say, for a project where kids are interviewing various people on a topic?

Cutting back on homework can make the difference in whether some students even attempt the assignment. And teachers who assign large amounts of homework are often unable to do anything more than spot-check it. Shouldn't teachers have the time to read homework closely, so they can see whether kids are learning?

One problem is that parents have trouble even finding out what the assignment is. This sounds straightforward, but parents for the most part only know what kids tell them. In this digital age, schools should communicate better.

Poorly thought-out assignments can make students cynical about school and crush their love of learning. I'm sure you've heard the perennial question, "Am I really going to use this after I graduate?" Some countries teach their children well without much homework. In Finland, for example, which ranks near the top in science worldwide, a half-hour of homework in high school is the norm.

Like many things in life, homework may be a case where less really is more.

This essay was first published in Newsday.