PROVIDENCE, R.I. — Rhode Island needs to make significant changes in its overburdened probation system, by lessening the time people spend on probation, making it harder to send them back for violations and better assessing who needs treatment more than prison, the staff of a special panel studying the issue said in a report released Tuesday.

Rhode Island has nearly 24,000 people on probation, supervised to one degree or another by about 63 probation officers. It’s a system that is becoming increasingly expensive and decreasingly effective, Governor Raimondo said in July when she signed the executive order that created the Justice Reinvention Working Group to study probation in Rhode Island.

The working group has been assisted by specialists from the Council of State Governments’ Justice Center, a nonpartisan association that studies governing policies and practices, including prison and probation programs, in other states.