The "No Child Left Behind Act" (NCLB, 2001) required schools to make adequate yearly progress, use disaggregated data in planning, and employ highly-qualified teachers. The school leaders became those responsible for the success of the school. In South Carolina the Department of Education has recently sought to address adequacy needs in response to the "Abbeville v. State" court ruling by improving the services offered at pre-school and elementary school levels (Hunter, 2005). Reducing the achievement gap is a major goal of public education today. Educational leaders must make crucial decisions promoting improvements as they are the primary link to sustainable educational reform (Fullan, 2002). The International Baccalaureate Organization (IBO) is a world-wide community of educational leaders who have exemplified successful influence in the overall success of public education. The problem is that no research study has been conducted at this time which demonstrates the long-term success of the IBO Primary Years Program in raising students' state test scores in upper South Carolina. With the state's new reforms addressing the pre-school and elementary disparities in student achievement (Hunter, 2005), the Primary Years Program may prove to be one of several viable solutions. The study contained in this document was conducted to determine the impact of the Primary Years Program on the English Language Arts Palmetto Achievement Challenge Test (PACT) scores of third, fourth and fifth students of an elementary school in upper South Carolina. The results of this research may be used to help determine to what degree this program is reaching its school district's goals of cost effectiveness and cause effectiveness in raising students' state test scores. The research presented here is a quantitative study which examined the impact of the Primary Years Program (PYP) of the International Baccalaureate Organization (IBO) on the English Language Arts PACT scores of elementary students in grades three through five in upper South Carolina. The school with the PYP had a total enrollment of 610 students in grades K-5. There were 108 third graders, 97 fourth graders, and 96 fifth graders. The 16 other schools (which do not have the PYP) had from 316-589 total enrollment with 41-101 third graders, 31-104 fourth graders, and 31-108 fifth graders (E. Baker, personal communication, October 23, 2007). The PACT scores of students from the elementary schools in the district with and without the PYP were analyzed using ANOVA and t tests. The impact of gender, race, and lunch status were included in the study. The level of significance was set at 0.05. This study analyzed 28,948 third, fourth, and fifth grade students' English Language Arts Palmetto Achievement Challenge Test scores over a period of eight years (2000-2008). The analysis of the data from this study revealed there was significant statistical difference which indicated the PYP affected improvement in the English Language Arts PACT scores of the third, fourth and fifth grade students in comparing the scores of students in the schools studied. There was no statistically significant impact of gender, race or lunch status on the scores of fourth and fifth graders; however there was a significant statistical impact by gender and lunch status on scores of the third graders as indicated by this study. The third grade students in the reduced lunch classification within the school that was to become a PYP school had scored significantly lower statistically the first school year of this study, 2000/2001. In 2003/2004 the third grade PYP students in the free lunch classification had scores significantly higher statistically than the other third graders within the same lunch classification. This was the first year the PYP was implemented. It is also noteworthy the PYP third grade male students scores were significantly higher statistically than the other third grade males in the study for the school year 2005/2006. This may indicate the PYP assisted in decreasing the achievement gap in these students. The Rosewood International Elementary (PYP) School utilized specific educational approaches which may be adopted by other elementary schools. Their core curriculum and the essential learning approaches of the PYP are based on the belief that children of all academic levels bring prior knowledge to the learning situation and engage with the curriculum through the activities designed by the teacher, essentially a constructivist approach. It was noted that the gap between the statistically significant higher scores of the PYP and non-PYP schools did lessen over the last few years of this study. This may be due to several possible reasons indicated in this document. (Abstract shortened by UMI.) [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.]