This proposed work is focused on social-emotional competence, which is an important determinant of school readiness. School readiness, in turn, sets the stage for school success and fosters attachment, bonding and engagement with the schooling process. There is clear longitudinal evidence that school success and engagement, as defined in this manner, serves as a powerful protective factor against a host of later health risk behaviors and negative outcomes including violent delinquent acts, school dropout, teenage pregnancy or fathering a child, heavy drinking and drug use, and multiple sex partners (Hawkins, Catalano, Kosterman, Abbott, & Hill, 1999). This proposal outlines five years of research and development activities that will adapt the First Step to Success early intervention program for effective use with Head Start children. First Step is a collaborative home and school intervention program, delivered by a behavioral coach and lasting approximately two months, that is geared for regular kindergarten classroom settings and designed to help at risk children get off to the best start possible in their school careers. First Step is an early intervention designed to achieve secondary prevention goals and outcomes within the context of schooling. The primary outcome of the program's application is a substantial improvement in the target child's school readiness as expressed through enhancements in both teacher and peer-related forms of adjustment. The adapted version of the First Step program would provide Head Start consumers, staff and professionals with a proven intervention option that will produce the following benefits: 1) substantially improved school readiness, 2) amelioration and/or elimination of serious behavior problems such as aggression, opposition-defiance, and other indicators of emerging antisocial behavior and externalizing behavior disorders, and 3) improvements in the target child's critically important relationships with the key social agents of parents and caregivers, teachers and peers. This proposed work addresses the rising tide of young children, having very challenging behavior problems, who have increasingly overwhelmed early childhood staff in preschool, Head Start and kindergarten classroom programs during the past decade (See FAN, 2000; Knitzer, 1998). The First Step adaptation process will be planned during Year 01 of this proposed research and initially trial tested using single subject research methodology. In subsequent project years, a prototype of the adapted program version will be tested during a primary intervention phase, revised and retested in a secondary intervention phase, and finally replicated in another cooperating Head Start site involving the Siletz Native American Tribes of Oregon. A comprehensive dissemination and technical assistance/outreach training program of activities for the final adapted version of the First Step intervention will be planned in project year 04 and implemented during year 05.