School effectiveness and instructional leadership research over the past thirty years have largely concluded that principal effects on student achievement are small and indirect; it has been assumed that principal effect is important, but mediated through other school factors. To the contrary, this experimental study found that one-on-one discussions between a principal and a non-proficient student that focused upon the student's 2008 reading score and a goal for their 2009 reading score had a direct and significant effect upon the student's subsequent reading achievement gains on a state reading test. Students in the experimental condition who held discussions with a principal prior to the state reading test showed reading gains significantly larger than students in the control condition who had their discussions after the state reading test. The randomly-assigned subjects of this study (20 in the experimental condition and 21 in the control condition) were 41 of the 66 eighth grade students who made up the entire non-proficient population of a large suburban middle school. Student achievement gain was calculated as the difference between the predicted versus actual reading percentile score as reported by the state's value-added system of assessment. The results of this study provide hope and potential benefit to principals who are challenged by the urgent leadership imperatives of No Child Left Behind and who seek the most immediate and direct ways to improve student achievement. Given this study's encouraging results, further investigations should be made into the principal-student discussion effect upon students of different genders, of different grade levels, and of different communities. [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.]