With the creation of the Institute for Educational Sciences over a decade ago, the U.S. Department of Education signaled a major shift in emphasis, aiming to support research “on which to ground education practice and policy and share this information broadly. By identifying what works, what doesn't, and why, we aim to improve educational outcomes for all students, particularly those at risk of failure.” The focus on what works has resulted in a substantial increase in the number of randomized controlled trials (RCTs) in educational policy research. An interest in understanding why educational policies and programs succeed or fail has led to the inclusion of embedded qualitative components in a large number of these RCTs. The value of mixed methods research—combining quantitative and qualitative data and methods—has been documented by policy researchers studying income supports for the working poor (Gibson-Davis & Duncan, 2005) and housing and residential mobility (Kling, Liebman, & Katz, 2005). The proposed panel provides new analyses from four mixed methods studies in educational policy research. This panel will highlight new empirical research from studies that use both quantitative and qualitative data to answer questions related to educational policy or program evaluation on a range of topics. The individual papers cover important areas of educational policy research, including a truancy intervention, a principal professional development program, effective high schools, and principal time use. Two of the four studies use data from RCTs with embedded qualitative components. The first paper uses interview and administrative data to understand the implementation of a large-scale truancy intervention in the Chicago Public Schools. The second paper examines the impact of Balanced Leadership, a principal professional development program, on student achievement. This study also uses qualitative data from case study schools to understand variability in implementation fidelity and program effectiveness. The third study uses longitudinal data from a mixed methods study of principal effectiveness to shed light on the time use and practices of effective principals. The fourth study uses a wealth of qualitative and quantitative data to describe an ongoing project aimed at scaling up effective schools that serve disadvantaged students. Taken together, this panel will illuminate the various ways that mixed methods studies can be used in educational research and will show the ways in which mixed methods research can improve our understanding of educational policy and practice. The discussant for this panel has extensive experience working on mixed methods studies in educational policy and other areas such as housing and residential mobility. In her critique and discussion of the panel papers, she will draw on her own experience with the advantages and challenges of mixed methods research in education policy.