Because data access may be perceived by principals as overwhelming or irrelevant rather than helpful (Wayman, Spikes, & Volonnino, 2013), data access does not guarantee effective data use. The data-based decision making literature has largely focused on teacher use of data, considering less often data-based organizational improvements for the school as a whole with the inherent focus on the role of the principal. The purpose of this study was to articulate the theory of change (Carman, 2010; Weiss, 1997a) which underlies the connection between accessing data via a dashboard, and the successful use of data to inform decision making by K-12 principals in their schools. This study's research question asked what knowledge, skills, and dispositions contribute to effective use of data dashboards by principals for school improvement. To answer that question, basic interpretive qualitative methods (Denzin & Lincoln, 1994; Merriam, 2002) were first used to outline the nature of dashboard use according to experts in industries where dashboards have a longer history and a more robust data technology literature base than in education. Then, with a case study design (Creswell, 2007; Merriam, 1988; Stake, 1995) and a focus on a data dashboard implementation in North Carolina, this study elicited program theory from North Carolina stakeholders. Data from interviews, observations, and documents were analyzed to articulate a theory of change and create (a) a logic model (a visual diagram) of how the dashboard is expected to facilitate data access and result in effective decision making, as well as (b) a logic model illustrating the theory-practice gap. Results of the study led to recommendations specifically for principals, ranging from developing spreadsheet skills to leveraging dashboards for situational awareness (Few, 2013; Marzano, Waters, & McNulty, 2005). In addition, the findings suggest that education planners should seek a true dashboard and refuse to settle for an interface offering a single sign-on to multiple software products. Further, schools need a framework for the action subsequent to data-based decision making. In the discussion of these findings, the study highlights the connection of Professional Learning Communities (PLCs) to principals and dashboards and offers insights from the business research literature about process improvement. This study has implications not only for the professional development of principals but also for the improvement of dashboard technology implementations, and for an expanded understanding of the potentially transformative impact of dashboards on decision making. [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.]