BJS was issued a data advisory on the State Court Processing Statistics Data Limitations. The advisory describes limitations of the data collection that must be considered when analyzing SCPS data, drawing any conclusions based on the data, and citing BJS reports.
The SCPS sample was a 2-stage stratified sample, with 40 of the 75 largest counties selected at stage one and a systematic sample of state court felony filings (defendants) within each county selected at stage two. The 40 counties were divided into 4 stage one strata based on court filing information. Ten counties were included in the sample with certainty because of their large number of court filings (though one was dropped due to data quality issues in 2009). The remaining counties were allocated to the three noncertainty strata based on the variance of felony court dispositions.