The beginning of probation officers’ engagement with groups of offenders happened during the phase of pro-social moralizing. The practice of employing youth groups was practiced and encouraged. The probation "home" was a controlled setting in which the probationer came in contact with others with similar problems. There is little evidence of officers working therapeutically with groups until the 1950's. The fact that there was an awareness of the power of group situations is evidenced by the club for the “unclubbables” established during the First World War. The practice of working with groups of probationers then was transformed from the use of activity as a vehicle for moral influence to a collective casework treatment. Group therapy and the use of camps were seen as new methods to be explored. There was some official support for this approach but its emergence as a viable form of intervention was primarily the result of individual innovation. The setting up of groups had an impact on the power relationship between probation officers and group members. Officers involved themselves in much more complex power structures than in one-to-one transactions. Groups loosened constraints on choice and self-determination. Those groups influenced by the therapeutic community model and its adherence to shared decision-making, group consensus, trust, and social learning made steps toward a new paradigm. Groupwork’s contribution to the gradual movement towards evidence-based practice constitutes the next phase of probation history. 28 notes, 54 references