This chapter builds on the previous two chapters in two ways. The recent literature on the effectiveness of penal interventions has emphasised the need to take account of dynamic variables1 (Andrews 1989; Jones 1996: 58). This chapter therefore investigates the most common changes experienced by probationers and the impact these had on their lives. It then moves on to consider the role of the officer in helping to foster these sorts of changes and, in so doing, ‘brings together’ the analyses of motivation, probation supervision and changes in personal and social circumstances.