Unit management restructures the administrative organization of prisons by subdividing the prison into semiautonomous units. Inmates are separated and managed according to classifications. Under AIMS, inmates are grouped into three basic categories of aggressiveness: "heavies," "violence-prone," and "manipulative predators." Inmates classified as "lights" are anxious, inadequate, victim-prone persons; the "moderates" are reliable, hard-working inmates. AIMS offers guidelines for inmate program assignments and treatment strategies as well as management recommendations regarding which matches between staff and inmates will be most effective. Measures for preventing inmate violence include training programs that help inmates deal more effectively with anger and environmental modifications that may include cubicles in dormitories, noise reduction, and increased privacy and safety. Policies that reduce prison overcrowding also lessen the likelihood of inmate violence.