The American Bar Association today recommended sweeping reforms in the way police, courts and correctional facilities handle juvenile offenders, including giving them the rights adults have to a lawyer and to a jury trial on criminal charges.

The standards passed by the ABA's policymaking House of Delegates would replace some of the paternalistic methods used by many juvenile courts across the country with the same rights accorded adult offenders.

Juvenile judges, for example, would have to sentence offenders to specific terms instead of leaving the amount of time to be spent in a correctional institution to social workers or probation officials. Sentences would have to relate to the severity of the crime -- not to what a judge or probation official thinks would be best for the juvenile.

In other proposed changes, juvenile criminal trials would be open to the public, juveniles would be allowed to see an attorney "at all crucial stages," and parents' role in proceedings would be lessened to avoid possible conflicts between the interests of parent and child.

Although the ABA delegates didn't approve four of the 17 volumes of recommendation produced after a 7 1/2-year study by a special committee headed by Chief Judge Irving R. Kaufman of the U.S. Court of Appeals in New York, most of the key elements survived.

"I think we have kept intact 95 percent of what we wanted," said Patricia Wald, an assistant attorney general and member of the committee who, before she joined the Carter administration, had led court fights to reform juvenile justice systems.

Beyond affecting the way juveniles would stand trial, the ABA recommendations set standards for police handling of juveniles and juveniles rights in correctional institutions.

Provisions which would have taken noncriminal offenses such as truancy and simple misbehavior from juvenile courts and would have separated probation functions from the courts drew strong opposition from the ABA delegates and were withdrawn by the Kaufman committee. But Kaufman said he will resubmit them next year after the delegates have had more time to consider them.

Although the ABA action changes no laws, it is expected to stimulate reform by state legislatures. Kaufman said that states have already borrowed "great big blobs" of the committee's recommendations as a result of preliminary reports on its studies.