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 Pennsylvania sample was separated into an elementary school sample (Grades 3 through 5) and a middle school sample (Grades 6 through 8), each consisting of three successive cohorts of students enrolled in school years: (1) 2007/08 through 2009/2010; (2) 2008/09 through 2010/11; and (3) 2009/10 through 2011/12. The initial sample included students across the three cohorts whose Grade 5 (elementary school sample) or Grade 8 (middle school sample) Pennsylvania System of School Assessment (PSSA) English language arts or mathematics scores on the general or alternate assessment were included in the state calculation of Adequate Yearly Progress (AYP). Although variation existed from cohort to cohort in sample demographic characteristics, generally the composition of the samples was quite similar across the three cohorts and for mathematics and English language arts at each grade level band. From elementary to middle school cohorts, there were small but consistent decreases in the proportion of English learners (EL), economically disadvantaged students (EDS), racial/ethnic minority students (i.e., American Indian/Alaskan Native, Asian/Pacific Islander, Black/African American, Hispanic, Multi-Ethnic, and Declined to report), and students with disabilities (SWD). The outcome measures for all analyses were the standardized Pennsylvania System of School Assessment (PSSA; Pennsylvania Department of Education [PDE], 2008, 2009, 2010, 2011, 2012) mathematics and English language arts tests. The PSSA is a summative, standards-based, criterion-referenced paper-pencil assessment aligned with PA Academic Standards and designed to assess knowledge and skills described in the PA Assessment Anchor Content Standards (PDE, 2008, 2009, 2010, 2011, 2012) which vary by grade and content area. This report discusses the results of the study in three sections. Section A describes school performance model estimates, Section B describes school ranks, and several appendices provide additional detailed results. [For the Oregon results, see ED585089. For the Arizona results, see ED585156. For the North Carolina results, see ED585157.]