The purpose of this study was to determine which qualities of effective teachers K-12 public school administrators and teachers in the United States perceive as having the greatest impact on student achievement. Stronge's (2007) meta-review of the qualities of effective teachers served as the framework for the study. An online survey based on that framework was deployed to a random stratified sample of administrators and teachers across the United States. Participants ranked five general teacher qualities and 29 indicators of quality in the order in which they believed them to impact student achievement. Participants were also provided an opportunity to list and describe additional teacher qualities they believed impacted student achievement that were not present in the survey. Descriptive statistics and ANOVA were used to determine the level of agreement between administrator and teacher rankings. Rankings were further analyzed to determine the impact that the following demographic factors had on perceptions: (a) region of the country, (b) urbanicity, (c) level of school, (d) years of experience, and (e) gender. Results indicated a strong level of agreement between administrator and teacher perceptions. Further results showed that demographic factors played a minimal role influencing participants' perceptions. [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.]