This report is concerned with the development and use of the Infant/Toddler Interaction and Activity Profile in 13 day care centers in Philadelphia. The Profile and its development are described and methods of data collection and analysis are explained briefly. Findings are reported in four major areas: (1) basic data characteristics, offering a general picture of infant/toddler care; (2) specific characteristics of adult responsiveness to children; (3) types and frequencies of observed interactions and their relationships to principles of child development; and (4) a system, based on preliminary data, for making discriminations between care rooms and demonstrating areas of strength and weakness. A summary of the findings about the instrument itself and the information collected is presented. Implications for further evaluation are offered. Appendices give definitions of the terminology used in the Profile and provide a sample observation record. (Author/JMB)