This guide for creating, instituting, and maintaining assessment portfolios is a professional resource intended for teachers seeking a realistic and manageable approach to implementing one aspect of authentic assessment--portfolios. The guide explains the philosophy of portfolio assessment and the benefits of using a portfolio system as a tool to create alternative and more authentic assessment, and includes practical advice about creating and using such a system and sample forms and examples from actual classroom portfolios. Specific chapters address: the difference between grading and evaluation; the four S's of assessment--students, style, subject, and space; the assessment portfolio model; establishing a plan; introducing and evaluating portfolios; conferencing; the interdisciplinary connection; and common questions and answers. (ND)