This technical report is one of a series of four technical reports that describe the results of a study comparing eight alternative models for estimating school academic achievement using data from the Arizona, North Carolina, Oregon, and Pennsylvania accountability systems. The purpose of these reports was to evaluate a broad range of models commonly used for estimating school performance that are applied in many states and frequently reported in the school effectiveness research literature. The introduction describes the study background and details the methods and procedures used to estimate the eight school performance models and compare model results in all four states. Details on each state's accountability data, assessment instruments, and results are included in their respective technical reports. The Arizona sample was separated into an elementary school sample (Grades 3 through 5) and a middle school sample (Grades 6 through 8), each consisting of the cohort of students enrolled in school years 2006/07 through 2008/09. The initial sample included all students whose Grade 5 (elementary school sample) or Grade 8 (middle school sample) reading or mathematics scores on the general or alternate assessment were included in the state calculation of Adequate Yearly Progress (AYP). School composition variables reported include the percent of English Language Learners (ELL), females, economically disadvantaged students (EDS), ethnic minorities, and students with disabilities (SWD). The outcome measures for all analyses were the mathematics and reading versions of the Arizona Instrument to Measure Standards (AIMS). The AIMS Reading (AIMS-R) and Mathematics (AIMS-M) are multiple-choice, standardized tests that were designed as dual-purpose assessments, providing both norm-referenced and criterion-referenced scores (CTB/McGraw-Hill, 2008). This report provides a summary and discussion of the results of the study. Section A describes school performance model estimates and Section B describes school ranks. [For the Oregon results, see ED585089. For the North Carolina results, see ED585157. For the Pennsylvania results, see ED585158.]