Much educational policy research can be conducted with existing data sources, either created for research purposes or for managing and maintaining information on public schooling systems. These often under-used resources offer rich research opportunities on the relationship between teacher and principal careers, school and district differences and student outcome changes over time. This paper describes how policy research involving rich data on actual schooling contexts remain critical to advancing individuals' understanding of contexts into which such reforms are to be implemented. Large scale, longitudinal universe data on state education systems provide invaluable insights into the "way" real public schooling systems work.