Developed by Lefton and Rosengren, the client biography model rests on two crucial dimensions: the variety of client behavior that the organization is interested in influencing and the duration of influence on that behavior. The first dimension is the lateral dimension; the second, the longitudinal dimension. In comparing probation with other sanctions, the dimension of duration of impact is probably less important than the dimension of extent of impact. In examining variations among strategies of probation supervision, factors to consider are the means of intervention, the organizational division of labor, evaluation criteria, relations with other agencies in the community, the management pattern, and types of interaction with probationers. These same six variables can also be examined as correlates of the duration of the intervention. These variables and the model itself could be important in some of the problem analyses and planning for change in probation. Some forms of organizational change may significantly impact what is expected of probationers; whereas, others may have little impact. One note and a list of 68 references are supplied.