High-stakes testing has become crucial in public education, requiring students to meet increasingly higher standards, regardless of their ability levels. This causal-comparative study sought to determine the effectiveness of an intervention mathematics course in the middle school setting for at-risk, sixth grade students. The Georgia Criterion Referenced Competency Test (CRCT) math scores of 143 at-risk students enrolled in a remediation mathematics course were compared to scores from a control population of 143 at-risk students who did not participate in the class. Math scores from the 2008 administration of the CRCT test were used as covariates, and comparisons were made using the 2009 math CRCT scores for students in the intervention class against scores from students not taking the class. Results showed that there were no significant gains in the scores of students who took the remediation class, regardless of ethnicity or socioeconomic status. However, statistically significant results were seen for the female population who took the class. These results imply that an extra math remediation class in addition to a regularly scheduled math class did not improve student performance on this particular high stakes test. Thus, alternative treatment formats may be considered, and more research in this field is recommended. [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.]