Background: Education seems to be in a state of constant change, though change initiatives rarely make it to the classroom in the manner and scope intended. Despite positive intentions and an enormous allocation of resources--money and time--the classroom has historically been buffered from the change context. A concrete manifestation of this buffering is the minimal implementation of changed instructional practices following participation in professional development. The loose coupling of the educational system--which is a descriptive way to capture the separation of levels and components in the system--results in a separation of intentions and actions, or intenders and actors. It is largely the school principal who is charged with overseeing the implementation of pedagogical improvements. Situating the school principal as change agent in this loosely-coupled system and what has in the past two decades become an accountability-laden environment, is necessary to reimagine the day-to-day functioning of instructional leaders when implementing change. Purpose: This study gathered self-reported survey data from public elementary school teachers in one district to learn about their preferences when implementing instructional practices following professional development and to find out what school leadership practices were associated with higher levels of implementation. The study answers the following two research questions: (1) What is the role of the school principal in the implementation of change? (2) What leadership behaviors are associated with higher levels of implementation? Data Collection and Analysis: A questionnaire was developed to address the two research questions. The content of the survey was grounded in scholarly literature and in my own experience as a school leader. Public elementary school teachers serving in one district in the Midwest provided the data analyzed in this study. The final analytic set comprised 260 teacher responses to the survey. The data from these responses were analyzed quantitatively for descriptive and correlational statistics to answer the research questions. Findings: The sample data from teachers showed clear preferences to guide school principals when leading the implementation of changed instructional practice. When engaging in professional development intended to change classroom practice, teachers expressed the following: Knowing the rationale for change was extremely important or very important (92% of respondents); Engaging in face-to-face training was extremely important or very important (52%); and Engaging in ongoing supports such as modeling and coaching was extremely important or very important (82%). The sample data from teachers also showed that the following four specific instructional leadership actions were associated with higher levels of implementation at the classroom level: Ensuring teachers know the rationale for change; Establishing the time and expectation of reflection on the change; Increasing teachers' knowledge of the instructional practice being implemented; and Systematizing the organizational routine of teacher collaboration. Conclusions: The data from this research illuminate actions to guide school principals when implementing changed instructional practice. These instructional leadership actions tighten the connection between intentions and actions and have leverage throughout the change process--before training, while engaging in training, and after training when implementation in the classroom occurs. The findings from this study provide evidence on what concrete leadership practices support teachers when implementing changed instructional practice. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]