When inmates enter the California prison system, they are classified according to the level of supervision required for them; the higher the security classification, the more restrictive the prison environment. The authors developed a new classification system to better predict inmate misconduct. The development process involved removing outdated items that have been shown to have no association with prison misconduct and adding several new variables that have proven useful in predicting inmate behavior. In order to test the new classification system, 20,000 inmates were randomly assigned to have their security level determined by either (a) using the standard scoring system or (b) using the new scoring system. Researchers focused on examining the key outcomes of amount and type of misconduct in prison and prison overcrowding. Results indicated that the new system performed better at sorting inmates according to their level of risk, especially in the case of predicting serious misconduct in prison. Although there is the potential of crowding problems, the new system is better than the old system in terms of accurate sorting and its ease of use. Tables, references