Since 1969, the National Assessment of Educational Progress (NAEP) has been the common yardstick for measuring the progress of students' education over time across the country. Teachers, principals, parents, policymakers, and researchers all use NAEP results to assess progress and develop ways to improve education in America. To make the relationships between NAEP and state education systems more explicit, governors, policymakers, and staff members of state education departments and large urban districts increasingly are interested in comparing their assessments, standards, and more (including content coverage, test items, and cognitive demand) to NAEP. State officials are major consumers of NAEP results and NCES reports that examine these results, trends over time, and aspects of performance. They want answers to key questions, such as: (1) How does NAEP compare to state assessments?; (2) Does NAEP measure the same general knowledge and skills that state assessments measure?; (3) Does a level of "proficient" on state assessments mean the same thing as "proficient" on NAEP?; (4) Are students learning what is being tested on state assessments and on NAEP?; (5) Does the relative standing of a group or subgroup (or groups or subgroups) of students remain the same regardless of the assessment?; and (6) How do NAEP results relate to and inform school improvement policy initiatives? The theme of "alignment" runs through these questions. That is, how well do states' assessments and standards match to NAEP? In addition, states might be interested in finding out how well their state assessments and standards align with other tests, including: (1) The Programme for International Student Assessment (PISA); (2) The Progress in International Reading Literacy Study (PIRLS); (3) The Trends in International Mathematics and Science Study (TIMSS); (4) Commercially available standardized tests, such as the ACT or SAT; and (5) Other measures they use or are evaluating for use. To assist states in answering their questions, NCES supported the development of three approaches that could be useful for state alignment initiatives: (1) The NAEP ESSI Procedural Manual; (2) The HumRRO Model; and (3) The Surveys of Enacted Curriculum (SEC) Model. This report will help states understand the three alignment approaches in terms of the questions they are designed to answer; the methodologies, tools, resources, analyses, and products they offer; and the amount of time and human resources they require. Additionally, this report includes: (1) A comparison table that highlights the key features, resources, and procedures for conducting an alignment study with each of the three alignment approaches; and (2) A glossary that will help states understand the different terminology used to describe assessments and alignment. State NAEP coordinators, state and district assessment and curriculum directors, and other state and district officials can use this information to compare and select an alignment approach or model that best matches their needs, expectations, and resources to achieve their alignment objectives. These alignment approaches also could prove useful to states interested in comparing their assessment systems to international assessments. Webb's "Depth-of-Knowledge" Model for Alignment is appended. (Contains 5 tables, 3 figures and 16 exhibits.)