The purpose of this study was to investigate the differences between exploratory children and cautious children as they functioned in open classrooms over a period of time and to document some general aspects of child behavior in open educational settings. Sixty children were observed through the course of the school year in their first grade open classrooms. Data analysis was focused on exploratory behavior in the classroom; patterns of mastery and learning; self-directed autonomous behavior, and relationships between teachers and peers. In general, it was found that differences between exploratory and cautious children were not so extensive as might be expected, and that not all predictions were borne out. There was no clear evidence that exploratory children were obviously more effective in open settings or that cautious children do not use the opportunities of the open classroom for learning and interaction. There were some systematic differences in functioning between exploratory and cautious children, however, and some patterns that characterized particularly the girls or the boys within the exploratory or cautious groups. The document includes a number of tables and detailed appendices. (MS)