Purpose of the study. The purpose of this study was to examine single-gender groupings for sixth grade mathematics classes as a strategy to improve student achievement. The method of research was quantitative, with MAP mathematics test data being used to determine if any relationship exists between the strategy and student achievement. Findings. From this study a firm conclusion about the value of single-gender classes is problematic. While the experimental group appeared to make a difference in the basic statistical analyses, the fact that the findings were not significant when a proxy measure for poverty (free and reduced lunch) and gender are both added to the statistical formulae raise substantial concerns about the value of single-gender classes. Further research is needed to better clarify the true value of single-gender classes compared to mixed-gender issues. [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.]