Accurate classification systems are therefore essential in the prison setting. Prisoners, like other people, adapt to their immediate environment and have the same types of needs which are common to all individuals. Rehabilitation programs must be offered but not required. Prisoners must have a predetermined length of stay at the institution, and institutional programs must include gradual testing of the prisoners' suitability for release. These concepts were applied at the Butner facility, and findings were used to compare the rates of violence at Butner with all other institutions in the region. Although problems arose in interpreting incident report data, findings were positive for the Butner strategy. Prisoners housed at Butner did not see the institution in a particularly negative light, and the staff view the Butner approach as being effective. Forty percent of the correctional officers reported being very involved in their work. Clearly written guidelines should specify the operational philosophy of a correctional system and thus reduce the ambiguities of the prison environment. The article provides 53 footnotes.