Research shows that planning and reviewing are the two components of the program day most positively and significantly associated with children's scores on measures of developmental progress.       These are the social, intellectual, and physical experiences that are essential to young children's optimal growth. The key experiences are organized into ten categories that comprise social development (initiative and social relations), visual and performing arts (creative representation, movement and music), reading (language and literacy), and math and science (number, classification, seriation, space, and time). High/Scope teachers keep these experiences in mind when they set up the environment and plan activities to encourage learning and social interaction. They also form the basis of High/Scope's child assessment tool - the High/Scope Child Observation Record (COR).