In the New York City high schools, three change strategies have been used to improve a system which, in and by itself, is dramatically changing. The high school system has undergone significant changes in purpose, organization, culture and student performance. The first change strategy established a partnership between the high schools and the Economic Development Council, a non-profit organization which brings resources of the business community to the assistance of the public sector. The second strategy was the Data-Based Management by Objectives System which emphasized planning and accountability. The third strategy involved identifying a major school issue (dropouts) and forcing attention toward the issue in order to create a demand for change. Each major change strategy had significant strengths and limitations; each provides important insights for other school systems struggling with the process of planned change. The New York Experience demonstrates the need to develop change models that are interactive and responsive to continuing change in highly open systems. (MJL)