An ongoing study by the Center for Criminal Justice at Harvard Law School praises recent reforms in the Massachusetts Department of Youth Service's treatment of delinquent youths and urges continued expansion of the reforms.

According to the study's third annual report, released January 15, Massachusetts juvenile institutions before 1969 were not serving as effective treatment and guidance centers for troublesome youths. Reforms have attempted to rectify this problem by decentralizing treatment facilities and diminishing their size, the report said.

The result, the report concluded, is that newer facilities offer more personal attention and can provide substantially better training for juveniles.

According to the report, the reforms comprise seven areas, including de institutionalization and the decentralization of correctional facilities, and programs for disturbed or dangerous offenders.

Theraputic programs were hampered by the rural isolation of large institutions, the report said. Their harshness and impersonal atmosphere was often unnecessary, and was destructive for youthful offenders.

The recent reforms have led to the closing of two large facilities, and have replaced them mostly with "cottage units," housing 10 to 20 youths with "houseparents," said Lloyd E. Ohlin, professor of Criminology and director of the study.

These units are in urban rather than rural areas, and attempt to foster vocational training and guidence within the community, the report said. In addition, some units now operate on a non-residential basis.

The Department generally recognizes that although most youths who are locked up need not be, some youths continue to be securely confined. The report urged continued attempts to distinguish between these types of youths.

The report also urged the Department to increase further the purchasing of psychiatric services for disturbed youths.

The study began in 1969, about the time Jerome Miller, commissioner of the Department of Youth Services, took over. The study was not related to Miller's appointment.

Miller, who has now resigned to take a similar post in Illinois, quickly instituted unprecedented reforms in the State's handling of delinquent youths.

"What came before [Jerome] Miller's administration was certainly not working," Alden D. Miller, a research associate in the Center for Criminal Justice and one of two full-time directors of the youth study, said yesterday. Miller described the reforms as by far the most rapid and advanced of their type in the nation.

The study, funded since 1969 by the governor's committee on Criminal Justice and the National Institute of Justice in Washington, D.C., will run for at least two more years, Ohlin said.