The purpose of the study was to compare the relationship between grade eight English language proficiency as measured by the ACCESS for ELL's assessment (Assessing Comprehension and Communication in English State to State for English Language Learners) and achievement test outcomes on the Pennsylvania System of School Assessment, a state mandated test. The ACCESS for ELLs is an annual, large-scale English language proficiency assessment given to kindergarten through grade twelve students who have been identified as English language learners. The ACCESS assessment is administered in English. Data from the Nation's Report Card (US. Department of National Center for Education Statistics, 2007a & 2007 b) show that ELL students lag behind their English proficient peers on standardized tests of reading. The inclusion of English language learners in state assessments has prompted issues regarding the validity and equity of assessment practices (Abedi, 2004). The data for the study were gathered from an analyses of 8th grade ELL students' scores on the 2011 PSSA standardized assessment test administered in the Philadelphia, Pennsylvania public school district. Data were also gathered from the analysis of 8th grade ELL assessments for the 2010-2011 school year. The study also assessed the predictive values of the criterion variables and the moderating effects of categorical variables by school: Ethnicity (Black, White, Hispanic), ELL status (English Language Learner), Students with Disabilities status (SWD), Socioeconomic status (SES), which contribute to Pennsylvania's Adequate Yearly Progress (AYP) status. The study showed strong evidence that there is a significant relationship between the PSSA and language background as measured by the ACCESS assessment. Assessment. The implications of these data for the testing and assessment of ELL learners was discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]