The current climate for education at the local, state, and federal levels includes an increased reliance on standardized assessment scores. Policy makers accentuate the need to raise standards of curriculum being instructed, accountability for assessment scores, and develop plans to close achievement gaps. Tests are given in grades 3 to 8 in math, Language Arts Literacy (LAL), and science. Additionally, tests are given to high school students for math and LAL, with a movement towards end of course exams specifically designed to align with high school course curriculum. Policymakers seem to think that all students can be assessed on the curriculum through a common instrument to measure student achievement. There are many factors that affect a student's capability to understand what is being instructed in school. Each student may come to school with his or her own learning disability (special education students, SE) or may be learning English (English language learners, ELL) as a new language. Also, there are many external factors that have an impact on student achievement. NJ has a model to measure scores of districts with common socioeconomic (SES) factors called District Factor Groups (DFG). The objective of this quantitative study was to use correlation and regression analyses to answer four questions that guided the research. The four questions were: 1) What is the predictive nature of the GEPA scale scores for the HSPA (grade 11) scale scores in math for all students in a B-DFG school?; 2) What is the predictive nature of the GEPA scale scores for the HSPA (grade 11) scale scores in math for general education students in a B-DFG school?; 3) What is the predictive nature of the GEPA scale scores for the HSPA (grade 11) scale scores in math for English language learners (ELL) students in a B-DFG school?; and 4) What is the predictive nature of the GEPA scale scores for the HSPA (grade 11) scale scores in math for students with disabilities (SE) in a B-DFG school? These findings will help school administrators and teachers with improvement plans to close achievement gaps by increasing student understanding thus improving assessment scores. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]