Principals need to be leaders who set and communicate a vision for learning, understand organization development, know how to effect change, are able to help teachers grow in their craft, and can interpret and utilize data for school improvement. The literature has shown disconnect between principal preparation and actual practices needed for the current era and complex role. States, universities, and school districts are redesigning preparation programs aligned with leadership standards to incorporate the components necessary for principals to achieve success in today's multifaceted role and the expertise to be able to increase student achievement. This mixed-method case study used the ISLLC 2008 framework concepts of vision, culture, management, collaboration, integrity and context with elementary, junior high, and high school principals in a southwestern, unified school district to determine if perceptions of success were developed individually, with district in-service training, or if their pre-service program was the contributing factor to their effectiveness. The School Principal Preparation Survey instrument was used to investigate what type of preparation led to principals' perceptions of success. Additionally, a focus group interview provided further insight into specific skills and themes addressed in the quantitative survey. Descriptive statistics and ANOVA were used to compare mean scores from principal responses to the Likert-scaled survey to determine if differences existed between principal groups on the variables of school level, time period of pre-service training, and training type. Responses from the focus group interview were transcribed and coded and then themes were aligned to quantitative results. The results indicated differences among principals by school level in the category of vision and among groups trained during five different time periods in the categories of vision, culture, management, and integrity. Focus group responses identified types of skills and training needed and individually developed no matter the length of service nor school level such as self-motivation, challenging assumptions, aligning resources to the vision, ability to adapt, and time management within the concepts of vision, integrity, and context. Agreement across school levels supported quantitative results indicating that most skills were individually developed, practiced in-service, or taught through mentors. Furthermore, no matter the time period trained, principals agreed that individual development of themes conveyed supported quantitative findings when comparing individual attainment to pre-service or in-service training in the categories of vision, culture, management, and integrity. Agencies must work together to revamp current programs and create policies and preparation programs to recruit, select, train, and retain principals reflective of the skills identified through strong internships with mentors, alignment to standards, and specific strategies for prioritizing and managing time, as well as how to bring stakeholders along with their vision. In-service training must continue while in practice to assist principals as they work toward increasing student achievement and preparing future workers and community members. Only then can effective principals provide what schools and students need. [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.]