From the Document: "The past three decades have witnessed considerable changes to prison classification systems. Before 1980, only the California Department of Corrections and the Federal Bureau of Prisons used objective classification systems. Subjective classification, which relied heavily upon the judgment of a wide array of prison officials to determine where a prisoner would be housed, and under what forms of supervision and security, was used at that time by practically all of the state prison systems. Since 1980, virtually all 50 states as well as Puerto Rico and the Virgin Islands have fully implemented objective systems. [...] Out of the wide proliferation of objective classification systems has grown a body of literature that has helped to shape and modify the first generation of prison classification systems. Some of these classification studies have been conducted by state prison systems while others have been sponsored by federal agencies- in particular the National Institute of Corrections and the National Institute of Justice. The purpose of this report is to summarize the new information and knowledge learned. Based on these 'lessons learned,' suggestions are offered to show that credible and valid classification and risk assessment systems are needed now, more than ever, to improve correctional operations and performance while reducing costs and recidivism."
National Institute of Corrections: https://nicic.gov/