The growing multidisciplinary literature on sleep and development needs to be integrated to yield organizing principles and conceptual frameworks researchers can use to defi ne and measure key constructs. This Monograph has three major aims: to present contemporary conceptual and methodological issues that need to be considered to integrate knowledge of sleep and child development across multiple disciplines, and accelerate the pace and enhance the quality of research (Chapter II); to discuss various sleep methodologies including their advantages and disadvantages (Chapter III); and to provide examples of longitudinal studies, which are needed in this developing area of inquiry, that demonstrate linkages between various sleep parameters and child development across multiple domains (Chapters IV through X). Chapter I introduces the main objectives of the volume, highlights the importance of sleep for child development, and presents a guiding framework for understanding the multiple influences on child sleep. Chapter II summarizes the outcomes of an SRCD sponsored forum on sleep and development that included scholars from multiple disciplines and presents guiding recommendations for research priorities. Themes include biobehavioral mechanisms, family processes, and socio-cultural factors; in addition, open questions and best practices in research design and statistics are discussed. Chapter III presents various sleep assessment methodologies including their advantages and disadvantages. Empirical studies (Chapters IV through X) were solicited from researchers in the fi eld; have a longitudinal element in their designs; demonstrate linkages between various sleep parameters and other key developmental domains; and use objective assessments of sleep duration or quality of "typically" developing children. Chapter XI summarizes key aspects of the various studies presented in this monograph and provides directions for this trans-disciplinary area of research.