Because privately operated correctional facilities are charting relatively untested areas, evaluators will be unable to turn to an existing body of data to assist them in anticipating future events. Another obstacle is the difficulty of developing sufficiently sensitive monitoring mechanisms to detect departures from anticipated circumstances. A significant obstacle to the effective evaluation of corrections privatization is the practical interests of politicians and criminal justice practitioners that dictate limited interest in the lengthy periods required to conduct the preprogram analysis required for effective evaluation development. Other obstacles, such as staff reluctance to cooperate fully with evaluation data collection, reflect the economic structure characteristics of private enterprise operations. Although most of the obstacles identified can probably be overcome with an adequate investment of time and resources, whether the costs of such an investment offset the apparent advantages of private-sector efficiency is debatable. 16 references.