The revised Individuals with Disabilities Education Improvement Act (IDEA, 2004) has offered a change of practice regarding the identification of students with a learning disability. Under IDEA (2004) educators are encouraged to use Response to Intervention (RTI) as a method to determine eligibility for special education services. In an RTI process, regular education and special education teachers review the performance of all students and jointly make decisions on how to support those who are struggling. Principals in particular need to understand the fundamental components of RTI and the strategies necessary for leading an effective implementation. There is limited research on the role of the principal in an effective RTI implementation process. This study aims to fill a void in the research on how a principal navigates the implementation of such a large-scale school-wide reform effort. In their seminal research study, Hall and Hord (1987) identify principal leadership as critical to successful change initiatives. The principal needs to have a keen understanding of the RTI components in order to make informed decisions about the required allocation of resources such as personnel, time, and materials to successfully implement this model. Leithwood, Day, Sammons, Harris, and Hopkins (2006) found that a leader has an impact on learning by charting a clear path, articulating high expectations, providing professional development, and creating an organization that supports teaching and learning. Successful leaders also improve teaching and learning by distributing the leadership. Sailor (2009) believes that the complex transformation to RTI requires the collaborative and shared responsibility/authority that is characteristic of distributed leadership. While acknowledging the importance of instructional leadership, he cites the complexities of RTI that warrant efforts beyond those of a single leader. Principals need to understand the change process as it relates to implementing a school-wide reform initiative. Fullan, Cuttress, and Kilcher (2005) propose eight "drivers" that are key to create effective and lasting change:1. Engaging people's moral purposes 2. Building capacity 3. Understanding the change process 4. Developing cultures for learning 5. Developing cultures for evaluating 6. Focusing on leadership for change 7. Fostering coherence making 8. Cultivating tri-level development (individuals, systems, and organizations). Fullan and his colleagues have found that successful change is contingent on leaders' knowledge of the change process and their ability to develop leadership capacity throughout the organization. Sailor (2009) suggests that leadership is the critical element for the change process. In a school where RTI has been successfully implemented, a systemic change has occurred. The principal plays a key role in setting the conditions for a positive outcome to the change initiative by understanding the research on school change and using this knowledge to successfully navigate through the process. The overarching question guiding this study was "What is the nature of the principal's leadership in elementary schools where RTI has been implemented?" This study investigated how an elementary school principal navigates through the implementation of RTI in his/her school, and how their leadership impacts the change process. The focus was on the leadership strategies used to effectively implement RTI, with the assumption that there is a strong level of instructional and distributed leadership. This study investigated the implementation of RTI through the lens of change theory. A multiple case study approach was used to provide the researcher with insight into the principals' and teachers' thoughts and experiences as they described the implementation of RTI during interviews. Observations of RTI meetings provided a snapshot into the types of leadership that emerged as the initiative was implemented. By also reviewing relevant RTI documents, such as meeting agendas, related memos, and notes from professional development, the researcher collected data to determine emerging themes regarding the leadership supporting this initiative. The data collected from these interviews, observations, and document review, informed the researcher on the leadership used to implement RTI in an elementary school. It was the researcher's goal to provide useful information to principals in the field as they initiate RTI in their schools. Four key findings emerged from the analysis of these data sources; the principal establishes clarity regarding the initiative by setting clear expectations and a school-wide vision, the principal distributes leadership during the implementation of RTI, the principal establishes frequent opportunities for the review of data, and the principal provides the organizational structure to support RTI. These findings lead to some clear recommendations for principals to consider as they embark in the implementation of RTI in their elementary school. Principals should establish clarity for the RTI initiative by setting clear expectations for implementation and a vision for RTI, with a clearly stated purpose. They should use student achievement data to provide a clear rationale for this reform. Principals should distribute the leadership throughout the implementation process. Coaches, specialists, counselors, and school psychologists can help "drive" this initiative by facilitating collaborative meetings, providing professional development, and acting as a liaison between the teachers and the principal. Teachers should be encouraged to take on leadership roles supporting the RTI model, within the school and during their data meetings. Open, two-way communication is critical to establish trust in order for collaborative decision-making to occur. Principals must establish data-based decision making as the nucleus of RTI. Opportunities to share and discuss data must be established so that through a collaborative process teachers can provide interventions to support their students. Principals must redesign their schools in order to support RTI. Schedules must be established to provide routine intervention blocks and collaborative meeting time, and the principal must act as the gatekeeper to protect these times. Resources such as personnel and materials need to be appropriated to support this three tiered model of instruction. These recommendations suggest the importance of the principal being well versed in the research on school change. An in-depth understanding of change theory will support the principal as he/she embarks on the implementation of RTI. The significance of this study is the provision of insight into the implementation of RTI ensuring higher levels of learning for all students. This study provides findings that will support other elementary school principals as they embark upon implementing RTI in their schools. Because implementing RTI will require a fundamental change in the way schools operate, it is critical that educators learn about the different models and make an informed decision before putting RTI into practice. The methodology and findings of this study provide a foundation from which elementary school principals can develop and facilitate RTI implementation in their schools. [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.]