Acting on complaints from media and parents, the American Civil Liberties Union is investigating reports that teachers are locking elementary-age students in isolation rooms as punishment for an array of infractions.

The ACLU announced the investigation at a press conference Thursday, noting that at least one complaint said youngsters were being locked in a small closet with no lights. The organization named Hawthorne and Dilworth in Salt Lake District, Westland in Jordan and Hillview in Granite.Lincoln Hobbs, director of the Juvenile Rights Project for the ACLU, said the agency has received a dozen complaints, both directly and indirectly. "Parents have called and complained, then said, `I know other parents who are upset about this, but they don't want to call.' Members of the press have contacted the ACLU and asked, `Have you heard about this?' "

Removing a child from a classroom and putting him in isolation for a short period of time is an effective disciplinary technique, educators in Jordan, Granite and Salt Lake districts said.

Spokesmen for the three districts also said they have had no complaints, formal or otherwise, about misuse of time-out guidelines, either in special-education or normal classrooms.

The ACLU has sent letters to the three districts, the Utah State Office of Education and the Utah attorney general's office asking for copies of the policies that guide use of time out for discipline.

District representatives said there are very specific guidelines and the technique is intended for use with children who have behavioral handicaps - and only with parental consent.

ACLU officials first want to know what the booths are like and when they are used. "We've had reports that they are being used for relatively minor infractions, like chewing gum in class," Hobbs said.

Some parents complained to the ACLU that they felt coerced to sign agreements allowing time out for handicapped students, said Michele Parish-Pixler, director of the ACLU.

Joyce Barnes, director of special education in Granite District, said removing children from their classmates for a short period of time is a discipline technique that is supported by educational research.

All three districts provide training to teachers who are allowed to use the technique and require them to pass a test on the subject.

An agreement with parents specifies the behavior that will trigger time out and the amount of time the child will spend isolated - usually a minute for each year of age, said Cal Evans, special-education director in Jordan District.

"One of the problems with certain types of handicaps is that the children act out their frustrations and become a danger to themselves and others. We can't have chaos in the classroom."

Barnes cited instances of children setting fire to classmates' hair and throwing metal wastebaskets when they were angry. One child sent eight people to the hospital with bite wounds, she said.

Patty Dahl, Jordan District spokeswoman, said the district's time-out boxes, located in four schools, are not unhealthful but are purposely designed to be boring.

Westland, she said, is not a school that has classes for handicapped children and should not be using the time-out policy.

Hillview, in Granite District, does have classes for handicapped children but not those with behavior disorders, and its time-out facility should not be used, Barnes said.

In Salt Lake District, Hawthorne does have a handicapped program, but Dilworth does not, said Jan Keller, district spokeswoman.

"We are not aware that rooms are being used for time out of regular classroom students," Keller said. "We've had no complaints in this regard that I am aware of. We'll be glad to investigate if someone does complain and gives us a little more information."