The purpose of this study was to determine the effect of a site-based technology coach program over the course of three years on teachers' perceptions of their implementation of NETS-T in a Tennessee school system. The study was a causal comparative study in which ten elementary schools had a site-based technology coach and ten elementary schools who did not. The participants were 507 elementary teachers from these 20 elementary schools in Williamson County, Tennessee. The Teacher Technology Self Assessment (TTSA) was administered through the Williamson County Intranet in the spring of each year of the study: 2006, 2007, and 2008. The TTSA was based on the six areas of NETS-T 2000: technology operations and concepts; planning and designing learning environments and experiences; teaching, learning, and the curriculum; assessment and evaluation; productivity and professional practice; and social, ethical, legal, and human issues. Independent samples t-tests were used to compare the participants. TTSA scores between the schools that had a site-based technology coach and those that did not. In 2005-2006, the data analysis revealed that the schools without a technology coach had significantly higher TTSA scores in productivity and professional practice. In 2007-2008, the schools with a technology coach had significantly higher overall TTSA scores as well as significantly higher TTSA scores in operations and concepts and productivity and professional practice. In conclusion, teachers improved their TTSA scores at a greater rate with a technology coach. Teachers had significant improvement with their own use of technology, but not with the use of technology with their students. It is recommended that further studies be conducted. A longitudinal study which examines the technology coach's effect on teachers' implementation of NETS-T over 10 years would provide data over different amounts of time. A study which examines the effect of different coaching strategies and the teachers' implementation of NETS-T would provide data to determine which coaching strategies are the most effective. [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.]