The ASPP collection is BJSâs most comprehensive source of information about persons under community supervision, which accounts for the largest segment of the adult correctional population in the United States. At yearend 2013, more than 4.75 million adults were under community supervision in the United States, including 3.9 million probationers and more than 850,000 parolees. About 7 in 10 persons under correctional supervision in the United States lived in the community in 2013, compared to 3 in 10 who were incarcerated in prison or jail. The ASPP collection fills a valuable role by measuring the number of persons under community supervision each year, the change in this number and factors associated with the change (such as movements onto and off community supervision), the characteristics of this population, and outcomes of supervision. These surveys collect information from both large and small agencies, which are located at various levels and branches of government and have highly diverse data record systems and resources.