Researchers interviewed 5,000 high school and junior high school students to find out what influenced their choices regarding marijuana use.

Among the findings:

Teens who feel close to their fathers are less susceptible to peer influence to smoke pot.

Teens' perceptions that parents would catch them for breaking "house rules" matters more than how much parents actually know about their children's friends and activities.

If parents are aware of rule violations, they should confront their teenage children rather than let them think they are getting away with something.

The most effective parenting approach combines love and support with clear rules and consequences.