The Mathematics Assessment Process (MAP) for the Middle Grades gives teachers and school reform leaders new tools to examine and systematically realign mathematics programs. MAP engages an interdisciplinary coalition within a school in an exploration of mathematics instructional excellence. Through an extensive self-study, a school answers the question, "How well is our mathematics program meeting the needs of the students in our school?" MAP integrates three central ideas: consensus on the need for major revisions in middle-grades mathematics, need to implement effective mathematics instructional practices targeted for adolescents, and existence of practical, tested strategies for planning change that can guide the restructuring of middle-grades mathematics programs. At the core of MAP is a set of "Criteria for Excellence" developed by a national advisory panel of middle-grades practitioners summarizing the principles underlying outstanding middle-grades mathematics education. This document, the "User's Manual," the first of a three volume set, contains six sections and appendices. Section 1 describes the trends in middle-grades mathematics and introduces the MAP "Criteria for Excellence". Section 2 explores the philosophic core of MAP, arguing that mathematics is a communication and problem-solving process. Sections 3 and 4 take team members through the approach to conducting MAP: collecting, analyzing and summarizing the data, and writing an action plan for implementing changes. Section 5 provides a staff development exercise to develop understanding of adolescents' mathematics needs. Section 6 provides annotated resource lists with over 250 references. The appendices include decision-making guidelines. (MDH)