The NSYC consists of an ACASI in which youth, using a touchscreen, interact with a computerized questionnaire and follow audio instructions delivered via headphones. The NSYC used self-administered procedures to ensure the confidentiality of the reporting youth and to encourage fuller reporting of victimization. The survey made use of audio technology to provide assistance to youth with varying levels of literacy and language skills.
Administrators in each state, county, and private facility determined the type of consent required for youth to participate. Youth who had reached the legal age of consent did not need permission from a parent or guardian. For youth under the legal age of consent, administrators in 129 facilities provided in loco parentis (ILP) consent. In 48 facilities, administrators provided parents with an opportunity to withhold consent; administrators in these facilities provided ILP consent for youth where the parent did not refuse consent (passive consent). In 150 facilities, administrators required that consent be obtained directly from the parents or guardians (PGC) of youth under the legal age of consent. In all facilities, youth also had to provide direct assent to participate in the interview.
Five weeks before data collection, the NSYC-3 project team requested that administrators in ILP facilities provide a roster of all adjudicated youth assigned a bed. In PGC facilities and facilities that employed both PGC and ILP based on the age of the youth, the project team requested rosters 9 weeks prior to data collection. The initial rosters were updated to reflect any additional youth admitted or discharged before the first day of data collection. Youth were randomly sampled from the initial and updated rosters.
Prior to data collection, field staff assessed the interviewing capacity at each facility. Capacity was based on the number of days, interviewing rooms, and available interviewers. In four large facilities, the youth were randomly subsampled so the number of sampled youth did not exceed interviewing capacity.
The final NSYC-3 universe represented 12,750 adjudicated youth held in state-owned or -operated juvenile facilities or placed in locally or privately operated juvenile facilities that met the eligibility criteria for inclusion in the sample. After subsampling, the final sample of youth was 12,362. A total of 6,910 youth participated in the survey, with 6,211 youth completing the sexual-victimization survey and 699 completing an alternative survey on topics such as living conditions in the facility, mental health, drug and alcohol use, and education.