Of the sample, about 1,000 were California Youth Authority (CYA) wards, and the remainder included 4 types of probationers: those on field probation, in private placement or juvenile halls on commitments of 30 days or more, and those in probation camps. The probation groups fell into a hierarchy of delinquency seriousness, with field probationers having the least serious records and camp wards having the most serious records. Among camp wards, those in secure or closed settings were more seriously delinquent than those in open settings. Compared to all other groups, CYA wards showed the most serious overall delinquency, showing more person and violent offenses, a higher number of petitions sustained, and more prior institutional and noninstitutional placements. Results clearly indicate that seriousness of delinquency is associated with disposition: the more serious the delinquency, the more security is involved in program assignment. Findings suggest that the protection of the public is a major factor considered by probation and juvenile courts in determining disposition. Data collection forms are appended. 20 tables.