This book describes the efforts of teachers to develop new strategies for looking at children's work and learning in three schools that are involved in the radical restructuring of education in concert with networks of reformers (the Coalition of Essential Schools, Foxfire, and Project Zero). The assessment strategies that these teachers are inventing are authentic in that they examine what students can do when they are engaged in real-world activities and the creation of their own ideas and products. The first half of each of these three case studies locates the teachers within the contexts of their schools to show the basic issues they face as they put portfolios into practice. The second half of each discussion describes the portfolios that have grown from classroom circumstances. The first case study looks at assessment in a second-grade classroom in Provincetown, Massachusetts (Project Zero). The second explores the development of portfolios in Bellevue, Washington (the Foxfire project), a team-taught multiage group, and the third focuses on high school assessment and the use of portfolios in Boston, Massachusetts (the Coalition of Essential Schools). In spite of the different environments in which they teach, these teachers share a commitment to facing assessment issues on behalf of their students. Three appendixes describe the three restructuring projects. (Contains 40 references.) (SLD)