John Elligers often contributes to the online comments that follow this column. He signs in as “LaborLawyer” and recently told me about how he violated one of the strongest and most senseless American educational taboos.

This is what he did: For one full day each year, he had the nerve to sit in the back of his children’s classrooms and quietly watch what was going on.

That hardly ever happens. Schools have many excuses for discouraging parents from observing what unfolds in classrooms. They say the presence of parents is disruptive, or violates teacher and student privacy, or requires too much time to arrange. Even requests for just an hour in class are rejected. Schools lack proof that such visits cause harm because they seldom let them happen.

To Elligers, this is ancient history. His last observation was in 1992. But he remains the only parent I have found who so often violated a taboo usually enforced by a school system. Parents may volunteer in schools, but their duties rarely include observations.

Elligers thinks the elementary and middle schools his children attended in Northern Virginia may have let him in because he had pull. “It probably helped that I was active in the PTAs and that may have led the principals to believe I could be trusted not to upset the classes,” he said. “It’s also possible that the principals thought giving me permission would be less risky than denying me permission. The principals knew that I was an attorney and that my PTA role was exclusively dealing with the County Council of PTAs on money issues, particularly pressing for higher county taxes to increase school funding.”

They may have feared he would go over their heads if they said no, Elligers said.

There were no disruptions. The few students who knew him smiled or waved and then ignored him. Teachers knew in advance he would be there. I think many parents would find the experience a bore, one reason schools are unlikely to be overwhelmed with requests if they decide to allow this.

Elligers and I — and several other people I know — love watching and listening to what our children are doing in class. We think it makes us better parents. Why shouldn’t we get a chance to do that if a stranger like me, by virtue of being an education writer, has been allowed to spend thousands of hours in hundreds of schools taking notes about what other people’s kids, and their teachers, are doing?

Elligers discovered something useful to any parent when he compared what he saw with PTA scuttlebutt. “The teacher reputations per the parent grapevine were sometimes not accurate,” he said. “In some cases, teachers with wildly positive reps were, in my opinion, barely competent, albeit entertaining, and teachers with drab or mildly negative reps were, in my opinion, doing an excellent job.”

The nonpartisan Education Commission of the States, a policy organization in Denver, told me it was able to locate only two states, California and Washington, that explicitly gave all parents the right to observe classroom activities. Some states allow parents to observe children with disabilities or disciplinary problems, but that’s it.

There is also an ill-considered reluctance to let parents observe classes in schools where they are thinking of enrolling their children. The school system in Arlington County, Va., one of the best-run in the country, allows parents with children already in the district to sit for an hour or so, but limits observations by prospective school parents to a pretty useless 10 minutes during the standard tour.

Other schools are worse. I know one couple who asked to sit in a class at a popular private school for an hour to ease their minds after they saw one child hitting another without staff members intervening during a tour. The school director said no, then added she was so troubled by their attitude she was tearing up their application.

It has been a long time since I watched my children in class. Those are important memories for me. I wish more schools would let it happen, maybe for a trial period. Then at least they would know if it caused harm or perhaps instead won the gratitude of conscientious parents like John Elligers.