This study examined the effect of small class size intervention on student outcomes using reading achievement scores as measured by the Comprehensive Test of Basic Skills (CTBS), a standardized, norm-referenced test, while controlling for independent variables inclusive of students' gender, race, socioeconomic status (SES), and environment. This study included students who participated in a randomized, long-term study, the Tennessee Student Teacher Achievement Ratio (STAR) experiment from 1985 through 1989. The STAR study took place in the Tennessee public school system, encompassing two groups of students: those who received treatment, small class intervention, 657 students, and students who did not, 5,689. Statistical testing included independent sample t-tests, one-way ANOVAs, regression analysis, and regression to test for significance between students who received small class intervention and those who did not. The study's results indicate a significant difference as measured by grade eight student outcomes amongst students who received intervention in primary grades, kindergarten entry through the end of third grade, and those who did not. Additionally, students' gender, race, socioeconomic status, and environment contributed to variability in student outcomes as measured by reading scores on the Grade 8 CTBS. [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.]