Rigid or flexible, zero tolerance policies on student behavior will not discourage disruptive student behavior, according to experts.

Those policies--which typically lead to student suspensions, expulsions and arrests for widely varying degrees of disruptive behavior--must be underpinned with programs designed to prevent bad behavior, experts say.

"Zero tolerance for violations only works if a school is taking action to reduce and eliminate a problem," said Larry Cohen, executive director of the Oakland, Calif.-based Prevention Institute, a nonprofit organization dedicated to improving community health.

"Those things, in my mind, tend to be lacking," he said. The result is that schools often boot out problem students without any plan for them, which only shifts the problem from the schoolyard to the streets, he said.

In an August 2006 report, the Washington-based American Psychological Assn. called on schools to relax their zero tolerance policies to reduce the number of students who are losing class time. The APA, citing 10 years of school violence research, encouraged schools to move to programs designed to prevent disruptive behavior.

Child psychologist Steven Dranoff said programs that help students negotiate through natural bends in the childhood road to socially acceptable behavior are preferable to zero tolerance policies.

But whether a school has flexible or rigid policies, school officials as well as students must "understand why kids do what they do," and students have to learn how to break the cycle of disruptive behavior, said Mr. Dranoff, president of D&D Industrial Consulting Inc. of Clifton, N.J.

The San Diego public school system added a behavior program to its zero tolerance disciplinary system with some favorable results, according to Earlene Dunbar, program manager for counseling and the guidance department.

Under the district's zero tolerance system, a disciplinary committee considers whether the school that is recommending suspension or expulsion for a student had an appropriate level of intervention in the area where the student violated school policy, Ms. Dunbar said.

To that end, the district three years ago implemented a program, designed by Mr. Dranoff, at a middle school with a history of significant student behavioral problems. Suspensions and fighting at the school have dropped considerably, Ms. Dunbar said.

Hoping for similar results, the district has recently implemented the program at two more schools.

In addition, officials are considering modifying the district's zero tolerance policies because of the research that shows "suspending students doesn't change behavior," Ms. Dunbar said.