The sample for the 2004 survey was selected from two different universe files: the primary file was a list 1,549 state prisons obtained from the BJS 2000 Census of State and Federal Correctional Facilities as enumerated on June 30, 2000; the secondary file contained 36 prisons which had been opened between June 30, 2000, and April 1, 2003.The sample design was a stratified two-stage selection, in which prisons were selected in the first stage and inmates to be interviewed were selected in the second stage. In the first sampling stage, 14 male and 7 female facilities were selected with certainty based on the size of the facilities. The remaining facilties were separated into 16 separate strata based on the geographic region in which the facility was located and the male and female populations in each prison. The weighting procedure consisted of a base weight for each inmate, and three adjustment factors that produced the final weight for the survey. Data were collected through face-to-face interviews with inmates using computer-assisted personal interviewing.

The questionnaire is modified with each iteration in order to capture information on evolving issues in criminal justice and topics of the greatest interest to users. Recent modifications include enhanced questions on medical and mental health histories of inmates.