There's more going on behind the scenes than most parents realize. Keeping these insider tips in mind will help you and your child.

When I was an elementary-school principal in Brooklyn, New York, young children were sent to my office for fist-fighting, shouting at teachers, writing mean notes, bringing a Civil War-era rifle to school for a history project, and peeing in a garbage can. Kids knew that I was the end of the line, and they arrived at my door with so much fear in their eyes that I never had to be scary.

I learned how to support and encourage children and their teachers on good days and bad. And I incorporated my perspective as a parent too; my daughters attended the school where I worked. I also came to realize that many of my fellow parents were confused and even angry about how schools handle discipline. So after five years of looking at things from both sides of the principal's desk, this is what I'd like moms and dads to know.

You should understand your school's approach.

Research shows that one of the most effective discipline strategies is authoritative: clear and firm, with only the most necessary rules, and supportive of kids' feelings. When consequences are necessary, children learn best from ones that are mild and immediate, along with positive reinforcement when they try to do the right thing.

Take the opportunity to learn about your school's discipline policy early in the school year, before anything goes wrong, advises Joanna Maccaro, a retired principal and facilitator for the Aspiring Principals Program at NYC Leadership Academy. Parents must be confident that the school's disciplinary policy will be followed in the event of a problem, no matter whose child breaks a rule. Usually schools provide written disciplinary policies online or during a back-to-school evening in the fall; if you don't hear, ask. Most schools use one of these approaches:

Assertive Discipline The teacher creates clear rules and employs a "discipline hierarchy" of three to six negative consequences for infractions; kids receive things like raffle tickets or marbles for good behavior so that they can earn rewards over time.

Positive Behavioral Interventions and Supports (PBIS) Teachers provide clear routines and expectations for various parts of school (classrooms, bathrooms, the lunchroom, buses). Kids practice these routines and teachers take time to "catch kids being good" as well as doling out predictable punishments for common infractions.

Responsive Classroom Teachers lead children to work together to create classroom rules at the start of the school year. Modeling helps kids notice and reinforce expected behaviors, such as raising hands and holding doors.

Effective consequences fit the crime -- and your child's developmental stage.

One day early in my tenure, a teacher brought 7-year-old Rowan to my office. He'd been throwing paper towels out the window, and the teacher expected me to do something serious.

Rowan's tearstained face betrayed terror and defiance. I weighed my options: soothe, yell, or try something else entirely? Once Rowan stopped weeping, I surprised us both by asking in an even voice what had happened. He eagerly told the truth. "I wanted to see if wet towels or dry ones fall faster."

I loved his curiosity, and it was all I could do not to grin. But then his voice dropped. "The teacher got mad. I get in trouble a lot." I understood my challenge. I had to help Rowan make better choices, and help him and his teacher see each other as partners rather than adversaries.

Rowan missed recess that day and wrote letters of apology to his teacher and the janitor. He helped the janitor replace the paper towels in all the boys' bathrooms and did such a good job he earned his teacher's genuine praise.

His experience taught me that it's helpful to focus on each child as an individual, to take time to find out what's going on, and not to yell. Kids respond well when you firmly clarify the rules and give them a chance to reflect on their choices. I insisted on sincere apologies (or at least convincing acting) and helped kids plan to do better next time. This allowed them not only to become better behaved but more ethical.

Consider yourself a partner with the school.

You can support your child's relationship with his teachers by explaining that school rules are to be followed, even if your rules are different at home. Young children feel confused when parents undermine the teacher's decisions.

I remember when one second-grader lost his temper and hit another child during recess. When his parents came in for a meeting, his mother was confrontational: "We teach him to stand up for himself. I'm glad he can use his fists." Her son looked at her and then at me, baffled about which of us was right. So I changed tactics quickly. "That is your rule at home," I said, "but the rules at school are different. No child is allowed to hit here. Not ever."

Other parents I called, on the other hand, were so embarrassed or so furious that they could barely talk with me on the phone. But the principal is not a prosecutor, and your child doesn't need a lawyer. Instead, she needs a parent who can stay calm and who is willing to work with the school to help her respect, reflect, and repair.

Accept that you can't know everything.

In talking to other moms and dads, I realized just how little most parents know about the disciplinary process in their child's school. Kids often give partial or confused accounts of the truth, and schools can't always provide lots of details when things go wrong.

One mom began to worry when her son Charles came home from school every day with "the Nicky Report." (In this case, names and identifying details have been changed, and the kids involved didn't attend my school.) "Nicky had a good day today," he might say. Or, "Nicky had a very bad day."

Other details emerged over time. Nicky had smashed the teacher's computer on the floor. He had tried to hit a classmate. The teacher had cleared children out of the classroom during violent outbursts.

The mom became increasingly concerned. When she asked the teacher for reassurance, she learned that school officials could not discuss how they were handling Nicky.

The Federal Educational Rights and Privacy Act states that parents must have access to all written records about their children and that no school can share information about any student without parental consent. This may mean that even if another child harms your own, the school can't discuss that other child with you.

But this doesn't mean there isn't a lot going on behind the scenes. When a student in my school had persistent behavior problems, our staff held regular meetings to decide how to help the child, and met often with parents.

Charles's mom was empathetic but was also in the difficult position of trusting the school without having much information. "The biggest failing of the school was in communication. It would have been nice to have a parent meeting explaining the safety plan and the protocol. Just saying 'We're following the school discipline code book' wasn't enough." The lesson: If something is going wrong involving another student, ask what's being done -- and what you can do -- to support your own child.

Tell the school about any changes at home.

This helps staffers better understand your child's behavior. Anna Strathman, who's been teaching at a California elementary school for 25 years, describes an eye-opening experience she had with one kindergartner who came to her classroom pushing, hitting, and using profanity. Eventually she called in the boy's parents. "They were angry at their son, at me, the principal, and the world in general," she says. When Strathman told them that their child was not only intelligent but often compassionate, the parents relaxed, telling her that he was wonderful with his younger twin sisters and helpful with his grandmother, who had advanced breast cancer. The meeting achieved its purpose, says Strathman: "Now I had a glimpse into their life, and they knew that I believed in their son."

It took several weeks, hours of intervention, and more trips to the principal's office to turn things around, but the child was able to learn new skills. "Now he's seen as a leader, the staff loves him, and he's always there to help his classmates," she reports. Building trust and working together on behalf of kids: That's the kind of success that makes me smile, as a principal and as a parent.

The Worst and Best Things to Say

To the Teacher Instead of: "How could you let this happen?" Try: "Tell me more about what happened."

To the Principal Instead of: "You've treated my child unfairly." Try: "Let's meet to strategize about how this can be avoided in the future."

To the Principal (when your child has been wronged) Instead of: "How did you discipline the other child?" Try: "Please explain the school's disciplinary procedure in cases like this."

To your child Instead of: "You'd better not embarrass us like this again." Try: "You look so sad. What are better choices you can make next time?"