|Of Special Note|
|State-level prison samples are not combined with the SAAL sample. Although the prison component includes state prisons, sample sizes are too small to be representative of a state's inmate population.|
|1992: A Look Back|
|A total of 1,147 inmates from 87 state and federal prisons were sampled in the 1992 NALS prison study.|
The NAAL prison sample is composed of 107 prisons, in 31 states and 12 federal prisons. It includes large states such as New York, Texas, Florida, and California (which contains the largest state inmate population in the United States).
Unlike the main NAAL’s four-stage sample design, sampling for the prison study consists of two stages of selection:
The first stage of sampling involves the selection of state or federal correctional facilities. The prisons were selected from the sampling frame, giving greater chance to the larger prisons.
The second stage involves the selection of inmates within each selected facility. Approximately 1,200 inmates were selected from the 107 prisons. The sample size of inmates selected for each prison was approximately equal in order to (1) provide an equal chance of selection for all inmates in the sample, and (2) arrive at close to equal workloads for interviewers.