In American public education today, a school can become successful or unsuccessful based on leadership. In this age of school reform, it is only appropriate to determine common leadership characteristics among successful educational leaders so that appropriate leadership training and development can be part of school improvement. This dissertation focused on the different types of leadership styles found in school districts, both at the building level and the district level. Moreover, this study focused on researching and finding which characteristics are present in school leaders who demonstrate Level 5 Leadership, based on the research conducted by Jim Collins in his book, "Good to Great." This study analyzed effective school leadership of administrators in the Tri-County area of southwestern Pennsylvania. All participants were administrators from the Allegheny, Westmoreland and Butler County areas of Pennsylvania. The purpose of this mixed methods study was to use the statistical results of the Effective Leadership Diagnostic Tool and qualitative interviews to determine similar characteristics that Level 5 leaders all possess. The findings were used to develop a professional development plan which is under development, for good administrators who aspire to become great leaders based on similar characteristics that Level 5 leaders all share with one another on their journey from "Good to Great." Three research questions were answered: 1) Given a survey instrument of key indicators of success, how would established school administrators rate each characteristic in order of importance from good to great? 2) How would these key indicators be used to justify the importance of each characteristic on a continuum? 3) What would a proposed professional development plan for training new and experienced administrators look like? The findings revealed that a number of conclusions can be made about the importance of six characteristics of effective leadership: 1) Disciplined Leadership, 2) Vision/Mission, 3) Effective Implementation of Decision Making/Consensus Building, 4) Cultural Change Agents/Communication, 5) Motivation and Self-Efficacy, and 6) Recruiting Self-Motivated People. Disciplined leadership, motivation, and passion were determined very important characteristics of effective leadership, and it is also important that school leaders confront the brutal facts about the future of American education reform in order to create and maintain successful schools. A healthy culture and team unity are important to a successful organization, as is the need for effective leaders to create a vision for the organization. Effective leaders also need to make good decisions in order to promote success within in the school. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]