The purpose of this study was to determine whether or not there was a significant difference in student assessment scores between eligible third grade students enrolled in the Central Maryland School District who participated in Supplemental Educational Services (SES) as opposed to eligible students who did not, relative to the Maryland School Assessment (MSA) test in reading and math. In addition, this study compared the effectiveness of varying levels of continuity in the provision of SES services (i.e., staying with the same provider versus working with different providers over several years). This study utilized a quasi-experimental research design. MSA reading and math scale scores were used for students who were identified as third graders in academic year 2007-2008, and fourth graders in 2008-2009. Using the causal comparative ex post facto method, a one-tailed paired sample t-test and one-way ANOVA were employed to explore the relationship between math and reading scores and SES participation and to identify whether the mean differences were statistically significant. A paired sample t-test and one-way repeated measures ANOVA test were used to explore the issue of continuity of provider services. Results of the study showed that there were no significant differences in reading and math scores for students that received SES when compared to students that did not. Similarly, when examining the issue of continuity, results revealed that continuity in provider did not show a significant difference. Specifically, the interaction of time and provider for both reading and math scores were not statistically significant when all of the providers were tested. [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.]