J. Mark Eddy's primary area of expertise is the development, refinement and rigorous testing of culturally informed multimodal preventive and clinical psychosocial interventions to improve physical and mental health outcomes for children and families. This work is done in collaboration with families and professionals from schools and other community-based service systems. Areas of interest include parent-child relationships; intimate partner relationships; family violence; parent management training; couples intervention; youth mentoring; early childhood education and family-based intervention; mothers and fathers involved with the juvenile justice or criminal justice systems and their families; children and families involved with the child welfare system; immigrant families; observational research; social interactional theory; coercion theory; cognitive behavioral therapy; longitudinal growth modeling; survival analysis; the development and refinement of effective communication processes between and among researchers, practitioners, and policymakers in order to provide children and families with the most effective preventive and clinical interventions; training and mentoring the next generation of implementation and prevention scientists.