A three-year independent evaluation of young women 12 to 17 who participated in the entire program, found the younger participants twice as likely to postpone sexual intercourse and the older participants half as likely to get pregnant.

After a three-year evaluation to work out any potential problems, the system is expected to spread elsewhere.

"During our three-year evaluation of the Newport proposal, it has become increasingly clear to us that the approval process will be lengthy and arduous," Nicholas C. Fanandakis, a vice president and general manager at DuPont, said in a statement.

The largest and most rigorous study of the program, a three-year evaluation of 1,600 Illinois families that was completed last week, found no evidence that the program saved money or prevented the splintering of troubled families in which parents have been reported for mistreating their children.

The report released yesterday is the last in a three-year evaluation designed to help the board make that decision.

The agency, in its own three-year evaluation, found that coded systems are unreliable and difficult to link with individuals.

Delivery of Local Road SafetyRoad Safety Research Report No. 124 The Department for Transport commissioned design and deliver a three-year independent evaluation of the delivery of local road user safety.

The study is part of a three-year evaluation of New York City's AIDS Education program financed primarily by the Robert Wood Johnson Foundation and conducted by N.Y.U. researchers.

Late last week, the Federal Centers for Disease Control and Prevention in Atlanta announced that a three-year evaluation of the Maryland and Texas systems had found that tracking H.I.V. by codes did not reliably count the cases.

The earmark had numerous critics, including global AIDS prevention advocates, the U.S. Government Accountability Office, and a Congressionally authorized three-year evaluation of PEPFAR by the non-partisan Institute of Medicine.