Political obstacles are difficulties that arise because all criminal justice agencies have multiple goals. Conceptual problems lie in the devising of a model that specifies appropriate connections between the actions of agency employees and the attainment of a chosen goal. Technical obstacles emerge in the form of methodological and statistical problems. In considering the impact of these obstacles on measuring police performance, attention is given to measures typically used to determine police crime control performance, the evaluation of police noncrime services, the relationship of police agency characteristics to arrest decisions, and the measurement of equity in the delivery of police services. One paper dealing with the evaluation of court performance considers methodological issues that arise in assessing the deterrent impact of sanctions' severity. Other papers that address the evaluation of court performance focus on how the deterrent effect of sanctions varies according to community context, and on methodological issues stemming from the measurement of equity in court decisions. In discussing prison effectiveness measurement, one study examines the current state of performance measurement, beliefs about the effectiveness of prisons, and an optimal plan for the evaluation of prison performance. Other papers consider research on the measurement of efficiency in corrections and researching effects of institutionalization on subsequent delinquency. Chapter references and data are provided. For individual documents, see NCJ 92181-90.