The Child Observation in Preschools (COP) is a system for observing children’s behavior in preschool classrooms across a day-long visit. The purpose of using the COP system is to provide specific information about how each child in a classroom spends his/her time. Although other observational tools examine the classroom from a top-down perspective, focusing on how the classroom is organized as a whole (e.g., what the teacher’s focus or intent is, how involved children are as a group), the COP allows for detailed glimpses into the classroom experience of the individual child. The COP is based on a series of snapshots of children’s behavior across a period of time. Each snapshot may be, by itself, an unreliable piece of information, but collectively, they combine to provide a picture of how children are spending their time in a classroom (as an aggregate), as well as information about individual differences in children’s experiences. (author abstract)