A third of parents don't think their methods of discipline are working very well, according to a study of 2,134 parents with children ages 2 to 11 in Canada, Puerto Rico and 32 states. The study appeared in the January issue of Clinical Pediatrics.

"I think if most parents are honest, the numbers would be even higher than that," says the study's author, Dr. Shari Barkin, chief of the Division of General Pediatrics at the Monroe Carell Jr. Children's Hospital at Vanderbilt University.

"It's a central element of parenting, yet it's difficult for many parents," she says.

"Usually if you have to do something every day you get good at it. But discipline is difficult and messy. There are so many factors. It's dependent on that particular child, that child's stage of development, that particular circumstance, that particular parent.

"For example, how I discipline my 3-year-old when he's hungry and tired requires a different strategy than what's needed when he's well rested and very verbal," she says.

Discipline is an area where parents need and want a lot of help but get little, Barkin says. She believes in-depth discussion about disciplinary strategies should be a regular part of well-baby visits — the series of recommended childhood checkups that generally focus on immunizations and the child's physical health.

Barkin says there are four principles to good discipline: