FrontMatter -- Preface -- Contents -- Executive Summary -- 1 Introduction -- 2 Characteristics of the Students, the Assessments, and Commonly Used Accommodations -- 3 Participation in NAEP and Other Large-Scale Assessments -- 4 Factors That Affect the Accuracy of NAEP's Estimates of Achievement -- 5 Available Research on the Effects of Accommodations on Validity -- 6 Articulating Validation Arguments -- 7 Implications of the Committee's Conclusions and Recommendations -- References -- Appendix Biographical Sketches of Committee Members and Staff.