The proposed study seeks to advance knowledge about community practice delivery systems that will enhance client participation and retention in the Early Risers "Skills for Success" conduct problems prevention program. The study will examine ways in which child, parent, and family characteristics associated with barriers to participation affect participation rates and outcomes in both center-based and outreach program delivery systems. The program will be implemented by Pillsbury United Communities [PUC], a nonprofit organization with neighborhood centers that serve economically disadvantaged, urban families, the vast majority of whom are African American. Children will be screened for aggressive/disruptive behavior during the kindergarten, 1st, and 2nd grades and PUC will implement the program over a three-year period. Project investigators will randomize these participants to either the Center-Based or Outreach program delivery models. Project investigators will conduct fidelity assessments of program implementation by agency staff and evaluate rates of client participation and retention, perceived barriers to participation and retention, and program outcomes. The specific aims are designed as a hierarchical series of steps to reflect a "goodness-of-fit" model that identifies specific patterns of child, parent, and family factors associated with significant improvements in the fit between psychosocial and demographic characteristics, rates of participation, and outcomes for each delivery system modality, controlling for levels of child aggression. Investigators will also perform an exploratory cost analysis of two reimbursement schedules (e.g., capitated model vs. fee-for-service model) associated with necessary differences in future funding of the two Early Risers program delivery models.