Ten years ago, a consensus existed that different sentences did not result in different levels of recidivism. As a result, observers argued that community supervision had to be justified by its greater humanity or economy than prison rather than by its greater impact on recidivism. However, further studies in Great Britain, Canada, and the United States challenged this conclusion. The emerging data now tends to support specific approaches to targeting programs to specific offenders, to ensuring that programs are highly structured and use broadly cognitive-behavioral methods, and have effective management and appropriately trained staff. Despite these findings and other positive developments, current national criminal justice policy is less favorable to probation than it was as recently as 3 years ago. However, the probation service will benefit by applying the findings of effectiveness research to a general strategy of improvement. 60 references