Last summer, a controversy erupted in an otherwise calm, small town in Maine. At Marcy's Diner, a group came in for breakfast on a busy Saturday morning. The group had a small child who screamed for over 30 minutes. Eventually, the owner of the diner became so frustrated that she went out and yelled at the patrons and their child.

A Facebook war exploded. Was the owner of the diner right to scream and swear at the child and the family? Or should the family have kept their child quiet so the other patrons wouldn't be bothered?

This raises a question that's a huge issue in parenting. It's hard enough to be consistent in disciplining your own kids, but it gets even harder when other kids are misbehaving. Here are some guidelines for disciplining other people's children.

1. Watch the behavior

Little kids make mistakes. They are still learning about social norms, and it might be best to just step back and observe. The child might stop misbehaving when he realizes that he's doing something wrong.

2. Judgment calls

If the misbehavior crosses boundaries, make some judgment calls. If the behavior doesn't stop, watch and decide if it's really that big of a deal. Parents tend to be overprotective, and if the behavior is only a little annoying, you should probably just leave the kids alone to figure it out themselves. If the behavior is hurting someone — emotionally or physically — then you should step in.

3. Address the problem

You can choose to address either the parent or the child, but always do so politely. Richie Frieman, a father and the Modern Manners Guy for MacMillian Publishing's QuickandDirtyTips, gives his suggestions here. If you don't know the disruptive child's parents very well, then it might be better to offer a suggestion or a joke, but if you know the parents well, you can afford to be more direct.

4. Have "house rules"

This means that you need to define acceptable behaviors for your own house. Your own children should be held to these standards wherever they are. When other children come to your house, explain the rules to them when they arrive so they know what to expect.

5. Agree on consequences in advance

This way, the children know what's coming, but it also helps you. You can't overreact and punish a child too severely if you already know what you need to do.

6. Give praise

Praise is much more effective than criticism. Give compliments to the children demonstrating good behavior, and the children are much more likely to obey because they want to, not because they're forced to.

7. Be consistent

Both with your own children and with other people's kids who are in your home, be fair and equal. Don't pick favorites or make exceptions.

8. Be forgiving

Children are still learning, so give them many chances. Give the appropriate punishment and then don't say anymore about it. Guilting children does more harm than good when you keep bringing up their mistakes.