At the onset of the 21st century, the United States ushered in a new era of school accountability and reform with the No Child Left Behind Act [NCLB] (United States Department of Education, 2010). Until and unless it is repealed or replaced, this law continues in effect today, with many states now applying to renew their NCLB waivers (Klein, 2015). Moreover, the responsibility for meeting the expectations of accountability and the need for ongoing improvement continue to rest squarely on the shoulders of school principals, many of whom may broadly understand data-driven decision making, but may lack the knowledge and strategic information to maximize the use of data findings in improving student achievement. The Mid-Continent Research for Education and Learning organization (McREL) has identified 21 leadership responsibilities that describe the knowledge and skills school leaders need to positively impact student achievement. This analysis centers around the McREL leadership responsibilities with an effect size of 0.25 or higher that require a focus on data. The use of hard and soft data to focus improvement is then analyzed and expanded upon through the McREL leadership framework lens.