These States were selected because they had successfully implemented objective prison classification systems (OPCS) modeled after the National Institute of Corrections prison classification system and were interested in learning about their systems and how they could be improved. The study included a process evaluation and an analysis of validation. Results revealed adequate numbers of professional staff trained and assigned to classification activities, high accuracy rates for both initial and reclassification instruments, and high rates of reliability for the scoring of the two instruments. However, parole violators who return for technical violations should be classified using the reclassification instrument, staff need ongoing training, and both States need an ongoing process or audit capability to better monitor the OPCS. Analysis of cases of inmates whose conduct did not match their security classification indicated the need for housing units and perhaps entire facilities for long-term and older inmates who require minimal internal security, the role of staff in suppressing or preventing serious incidents, and the role of the facility's physical characteristics in suppressing or increasing opportunities to become involved in serious misconduct. Findings supported the overall soundness of the system in terms of classifying inmates according to each agency's formal policies and procedures. Tables, appended interview instruments and case studies, and 11 references