This essay addresses the school improvement process based on Effective Schools Research (ESR) and its commitment to equitable and quality education for minority and poor children. After briefly discussing general attributes of ESR-based programs, the essay explains major premises of the effective school. The first premise sets teaching and learning as the primary schooling function, assigning secondary importance to custodial and sorting functions. Other premises concern assessment of student outcomes, monitoring, curriculum mastery, and equal benefits issues. To incorporate these research premises into school practice, the school leader must draw upon three sources of locally derived information: measurable student outcomes, socioeconomic status data, and specified levels of curriculum mastery. The school improvement effort depends on a shared vision and commitment of the school community and it demands staff and organizational development and planned change. Planning steps are described that focus on the needs assessment process and on characteristics of effective schools: (1) a safe and orderly environment, (2) a climate of high expectations, (3) sound instructional leadership, (4) a clear and focused mission, (5) opportunity to learn and student time on task, (6) frequent monitoring of student progress, and (7) supportive home-school relations. (MLH)