This study examined the relationship between the structural classroom environment (self-contained, team-taught, and departmentalized) and student performance on the 2014 Georgia Criterion-Referenced Competency Test (CRCT) in reading, Language Arts, mathematics, science, and social studies in grades three through five. A secondary purpose examined whether third grade CRCT reading scores could be predicted based on classroom environment for different ethnic, gender, and socioeconomic variables. Data was collected on 2,744 students enrolled in a school system in south Georgia. A MANOVA with Bonferroni's Correction showed significance in favor of a self-contained classroom in mathematics. Cohen's effect d showed effects of small practical significance. A four-factor analysis of classroom environment, ethnicity, gender, and socioeconomic status using an ANOVA showed significance when all four factors interacted. Results showed significance in most cases in favor of a self-contained classroom, although there were notable exceptions. The results indicated that poverty was a factor in every ethnic group. Cohen's effect "d" showed effects of small practical significance. Additional results with implications for school leaders concerning classroom environmental structure decisions are provided. Recommendations for further research are included. [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.]