This chapter examines how studies focused on the same topic--disproportionality in special education--can generate vastly different conclusions about its sources and causes. By analyzing existing disagreements in the field, we explore essential questions about what constitutes high-quality and relevant evidence when seeking to understand how, when, for whom, and why disproportionality occurs. Using a holistic review of the empirical literature on disproportionality, we illustrate how differing epistemological and ontological views inform research around the topic of disability in schools and argue that to develop high-quality evidence around disproportionality, researchers need a shared framework that describes how school-based disabilities and classification processes intersect. A shared framework will enable researchers to evaluate whether their findings are expected or unexpected, connect to other related research, and build and rebuild paradigms around issues of equity in special education, rather than disregard one set of findings over another.