In an effort to implement school reform to meet the needs of a changing society, schools have taken action to assist students in achieving proficiency on standardized tests by implementing departmentalized gender-inclusive classroom environments in the public school system. Research conducted in M. Gurian and P. Henley's (2001) "Boys and Girls Learn Differently", P. Tyre's (2008) "The Trouble With Boys", and M. Levine's (2002) "A Mind at a Time" suggests that there are gender differences among male and female students that become apparent in the learning environment. Since the changes to Title IX under the No Child Left Behind legislation in the United States, schools have been able to implement programs in the K-12 system based on gender differences. Single-sex classrooms are assisting schools with increasing student performance scores on standardized tests. In this study, a 2 x 2 factorial design evaluated the effectiveness of departmentalized gender-inclusive classrooms at the elementary level. The focus of this study was to determine if there is a statistically significant difference among student performance scores in the area of math and reading among departmentalized gender-inclusive classrooms compared to coeducational learning environments. The main goal of a departmentalized gender-inclusive classroom is to offer a higher quality of teaching with a focus on a single subject matter based on gender differences. This applied practice is currently implemented at the fourth- and fifth-grade levels at an elementary school located in central Florida. [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.]