The study involved 35 detailed, semistructured interviews with 27 probation officers of all grades, 5 justices' clerks and magistrates, and 3 senior treasury and information officers inside and outside the area probation service. The interviews were designed to elicit perceptions of probation effectiveness and the criteria by which officers and others saw probation performance being evaluated, both by themselves and by those to whom they were accountable. The probation agency examined has met the prime requirements and demands placed on it by those to whom it is chiefly accountable and been rewarded by a greater share of resources. The discussion of study results is oriented around a number of key themes including the respective prominence of input and output measures of performances, factors that influence and explain 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 study illustrates the socially constructed nature of the concept of organizational effectiveness and of management information systems. It highlights how pressures exerted on the probation service have de-emphasized the effects of probation supervision on criminal careers. This study reinforces the arguments of those who question the privileged status given to accounting-based solutions to the problems of public-sector management. 2 notes and 38 references