Early in childhood intervention is a young and rapidly growing field. In little more than a decade it has been transformed from an emerging service with a primitive empirical base, scant funding, and virtually no public mandate to a robust area of theory, research, and practice. Moreover, since the passage of the Education for All Handicapped Children Act Amendments of 1986 (Public Law 99-497), early intervention has acquired a growing national audience, increased funding, a promise of more comprehensive programmes and services, and unprecedented attention from major state and federal policymaking groups. The Handbook of Early Childhood Intervention has been designed to serve as a core textbook for those who are interested in young children with disabilities or developmental vulnerabilities, and their families. Its intent is to integrate the theory, research, and practical knowledge that guide current practice in this field and to frame the agenda for its continued growth and maturation. The editors of this volume have brought together an outstanding collection of contributions from many of the most creative thinkers and influential leaders in the field. The overall goal of the Handbook is to present sophisticated, state-of-the-art material in a format that is accessible to a broad audience that cuts across such diverse disciplines as education, psychology, social service, pediatrics, nursing, speech and language, pathology, occupational and physical therapy, public health, and child care. Within and across each of these professional domains, the Handbook of Early Childhood Intervention can serve as a definitive source for those involved in academic training programmes, research and scholarly endeavours, policy development, and service provision.