Abstract:This paper examines notions of probation effectiveness being applied in one metropolitan area probation service, and considers the impact of recent managerial and policy initiatives on the work and effectiveness criteria used by probation staff. The paper is structured around a number of key themes including: the respective prominence of input and output measures of performance; factors influencing and explaining the use of such measures; perceptions of promotion criteria and survival tactics within the service, and the role of management and management information systems. Through such themes, the paper illustrates the socially constructed nature of the concept of organisational effectiveness and of management information systems. In particular, it highlights how pressures being exerted on the service have served to deemphasise the effects of probation supervision on criminal careers. The paper adds further weight to the arguments of those who question the privileged status given to accounting‐based solutions to the problems of public sector managemen