This report presents findings from a study conducted by The George Washington University Center for Equity and Excellence in Education (GW-CEEE) under the sponsorship of the National Center for Educational Statistics (NCES). The purpose of the study is to describe and analyze school-based decision-making practices relevant to the inclusion and accommodation of English language learners (ELLs) in the 2005 National Assessment of Educational Progress (NAEP), which was administered as part of the Trial Urban District Assessment (TUDA). This study investigated how school personnel in urban districts make decisions regarding the inclusion and accommodation of ELLs in NAEP. The study explored the following research questions for a sample of four of the 11 TUDA districts for the 2005 administration of Reading and Mathematics assessments in NAEP at Grades 4 and 8: (1) What factors influenced decisions of school personnel regarding whether to include or exclude ELLs in NAEP?; (2) What factors influenced decisions of school personnel regarding the use of accommodations for those ELLs who were included in NAEP?; and (3) What was the relationship, if any, between the decision to include and the decision to accommodate? For ELL inclusion decisions, decision makers at 26 of the 29 sample schools across the four districts said they relied on ELL-responsive criteria--e.g., "language-related," "academic-related," "time-related," and "opinion-related" criteria. Data further indicated that decision makers applying ELL-responsive criteria had selected from a wide range of criteria from within this category. For accommodations decisions, the application of SD criteria was equally as prevalent as the application of ELL-responsive criteria. A review of the accommodations decision-making practices for the 29 schools indicated that 13 schools relied on ELL-responsive criteria, while almost as many schools (12) relied on criteria intended for students with disabilities. In sum, findings from this study reflect the complex interaction of decision-making practices with the school culture, district and state policies, and the pressures of daily existence in schools. These findings support the conclusion that (1) reliance on state assessment policy or classroom practice for NAEP inclusion and accommodations criteria may result in inconsistent and/or inappropriate decisions; (2) that school decision makers need a greater understanding of the needs of ELLs in relation to high stakes testing, in particular regarding the distinction between the needs of ELLs and those of students with disabilities; and (3) that stronger guidance may be needed from NAEP in order to assure the use of appropriate criteria to support the decision-making process. Appended are: (1) Interview Protocol for NAEP School Decision Makers; (2) Analysis Codes; and (3) District Overviews and School Profiles for the Four TUDA Districts. (Contains 3 figure, 34 tables, and 10 footnotes.)