Young children's self-regulation has increasingly been identified as an important predictor of their skills versus difficulties when navigating the social and academic worlds of early schooling. Recently, researchers have called for greater precision and more empirical rigor in defining what we mean when we measure, analyze, and interpret data on the role of children's self-regulatory skills for their early learning (Cole, Martin, & Dennis, 2004; Wiebe, Espy, & Charak, 2008). To address that call, this chapter summarizes our efforts to examine self-regulation in the context of early education with a clear emphasis on the need to consider the comprehensiveness and precision of measurement of self-regulation in order to best understand its role in early learning.