The first stage of the screening procedure relied on teacher reports of classroom conduct problems of 9,594 kindergarteners in three cohorts (1991–1993), using the Teacher Observation of Child Adjustment-Revised Authority Acceptance Score (Werthamer-Larsson et al. 1991). Children scoring in the highest 40% within cohort and site were solicited for the second gate of screening: parent-rated home behavior problems, using a 22-item instrument based on the Child Behavior Checklist (CBCL; Achenbach 1991a). Teacher and parent scores were standardized within site and summed to yield a severity-of-risk screen score. Children were selected for the study based on this risk score, moving from highest down until desired sample sizes were reached within sites, cohorts, and conditions. 979 children (10% of total) were solicited to yield a sample of 891 participating children (91% consent; intervention n = 445; control n = 446). At selection, participant mean age was 6.58 years (SD = 0.48). Ethnicity varied (51% AA, 47% EA, 2% others), and 69% were boys. The mean externalizing problem score for the Teacher’s Report Form of the CBCL (Achenbach 1991b) was 1.6 SDs above
