Effective ways of disciplining a child include time out, withdrawal of privileges and redirecting the child to other activities after a short verbal warning. Parents should also reward good behavior, as positive reinforcement makes children more likely to repeat those behaviors. Appropriate discipline methods vary depending on the child's age.
Time outs work well as a punishment for children between 2 and 5 years old because the child doesn't receive any attention. It's not a good choice for younger children, as they may get separation anxiety. The parent should completely ignore the child during the time out, and it should last one minute per year of age, at most.
Withdrawal of privileges is a good choice for children between 6 and 12 years old because they learn consequences of poor behavior. For example, the parent can take a favorite toy away for a period of time if the child misbehaves.
Since children under 2 years old don't understand the world very well, parents should be lenient with punishments. If the child does something wrong, the parent should say "no" and immediately give the child another activity to do. This teaches the child that the first action was wrong. The parent may also add a short explanation. For example, if the child hits the parent, the parent can say, "No, that hurts."