This case study presents findings from a year-long ethnographic study of an urban junior high school principal. It concludes one of seven studies conducted in elementary and intermediate schools in urban, suburban, and rural settings to investigate the instructional management role of principals. Although previous research offers disparate viewpoints about the potency of principals as instructional leaders and managers, this series finds that principals can significantly alter their schools' instructional systems and students' social and academic experiences. Using observations of principals' activities and interviews with students and staff, the seemingly chaotic behavior of principals may be construed as purposive. Activities compose nine categories (goal setting and planning; monitoring; evaluating; communicating; scheduling, allocating resources, and organizing; staffing; modeling; governing; and filling in). The purposes or targets behind principals' activities include work structure, staff relations, student relations, safety and order, plant and equipment, community relations, institutional relations, and institutional ethos. Principal Grace Lancaster's routine behaviors involved communicating; scheduling, allocating resources, and organizing; monitoring; and governing. Lancaster's primary target was work structure. Teachers perceived her as a supportive and effective intermediary with the district bureaucracy. Lancaster used her nonauthoritarian leadership style to create a safe, pleasant environment for staff and students, which allowed them opportunities to make choices. (Contains 64 references.) (MLH)