Dr. Kazdin, a psychologist who has helped many defiant children, has carefully studied and applied research on shaping children’s behavior. He’s seen great success in using programs where kids collect points for doing certain behaviors and then turn those points in for rewards. He’s captured this process in his book The Kazdin Method for Parenting the Defiant Child.
The method begins with parents thinking of the positive opposite of whatever behavior they want to stop. For example, if a child throws tantrums whenever it’s time to go to bed, then the positive opposite would be getting ready for bed, going to bed and staying there without screaming or hitting. Kazdin describes how to set up a reward system that encourages children in moving towards this new behavior.
One key aspect is that children are rewarded for small steps along the way. Parents are taught to give enthusiastic praise and points whenever a child performs a portion of the new behavior. The child can then earn rewards which can range from choosing what to have for dinner to earning a trip to the zoo. The reward program usually lasts only a few weeks until the child masters the new behavior.
You can learn more about the Kazdin method is his book: