As a challenge to traditional assessment, this paper describes how the work of a network of teachers to improve schooling through authentic assessment and practice may lead to a general reform of nearly all aspects of the educational enterprise. The paper springs from observation of participant teachers in the Four Seasons Project which is designed to promote significant school change by changing fundamental assessment practices. Four Seasons is a partnership of four school reform organizations: the Coalition of Essential Schools, the Foxfire Teacher Outreach Network, Project Zero, and the National Center for Restructuring Education, Schools, and Teaching. Chapter 1 explores why the teachers involved in this work have made their public commitment to develop authentic assessment and finds reasons in teachers' philosophies about teaching and learning in their autobiographical stories of experiences as students and teachers. Chapter 2 explores teachers' views of the relationships between curricula, instruction, and assessment as inseparable elements of authentic practice. Chapter 3 explores the difficulties, false starts, and mistakes in their experiences with authentic assessment. Chapter 4 describes classroom practice to portray how assessment, curriculum instruction, and relationships are woven throughout the classroom experience of teachers and students. Chapter 5 reflects on authentic assessment and its influence on systematic change. (Contains 37 references.) (JB)