In the United States, teacher certification has been a baseline measure of teacher quality and gateway to the teaching profession for many decades. Research suggests that teacher certification is beneficial to student achievement, with findings particularly promising when content area of teacher certification is taken into account. Positive findings are largely limited to high school. However, in recent years middle grades have been increasingly viewed as a starting point for success in high school and college, which led many school districts to require advanced training for middle grades teachers. To examine the effectiveness of advanced teacher training in middle grades, the study analyzed the nature of longitudinal relationship between student outcomes and teacher training in middle grades math and reading at one of the largest public school districts in the Midwest. Using a multilevel model of growth at the school-level of analysis, the study found a positive effect of advanced teacher training in math on student achievement in math. The study did not find evidence of the positive effect of teacher training in reading. Examination of the local policy context suggested that changes in the district could have impacted the study's ability to estimate teacher effect in reading. [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.]