This book investigates the most common approach to assessing behavior in youth development. It explores use of multiple informants who each observe youth in the social contexts that typify their everyday lives, including parents, teachers, peers, and youth themselves. The volume characterizes the most common outcome from taking this assessment approach — the discrepant results or estimates about behavior that informants’ reports often produce. Grounded in the Operations Triad Model — the foundational framework for contemporary scholarship about discrepant results — this book...