This grant application describes the theoretical background and research design of a project intended to study the interaction between children's styles of functioning and the opportunities and requirements of an open classroom environment. A major assumption to be tested is that exploratory children function more effectively in open classrooms. Other information to be documented includes: (1) different patterns of functioning; (2) the changes in functioning patterns over time; and (3) teacher interaction with more and less exploratory children. Supplementary investigation will focus on sex differences and socioeconomic differences in open classroom behavior. The project is planned to extend from September 1973 through December 1975 and will involve the study of 60 first graders identified as exhibiting a high or low level of curiosity and exploratory behavior through teacher rankings and individual sessions. The majority of the data to be analyzed will be collected through intensive classroom observation. Main variables to be examined include involvement with materials and activities, teacher-student relationships and interaction patterns, peer relationships, experience of mastery, and pleasure and involvement in the classroom experience. (SDH)