Focusing on the preconversational child who has yet to develop a stable or generalized habit of spontaneous conversation, this book presents ECO (Ecological Communication Model), a new intervention model for social and communicative development of developmentally delayed children. The model is based on two perspectives: the literature on the development of parent-child interaction in the first few years after birth and a series of clinical research projects that have investigated parent-child interaction within intervention programs. The unifying concept of the ECO model is partnership, defined as a generalized habit of balanced, reciprocal interactions maintained by a sensitively matched and responsive adult who is frequently child-directed and who fosters emotional attachment. The first part of the book presents the fundamental concepts of the ECO model, discussing the principles of communication development, and examines the five competencies on which the model builds: Social Play, Reciprocal Interactions, Preverbal Communication, Language, and Pragmatics of Conversation. The second part of the book provides developmental guidelines on how adult and child can become partners in play, turntaking, communication, language, and conversation. The third part presents the clinical studies on which development of the ECO model was based, and discusses future challenges and dilemmas, particularly the legal aspects, to socializing preconversational children. Contains 250 references. (AA)