Children develop and learn within dynamic contexts, yet the simplifying assumptions of common statistical methods often relegate such complexity to unexplained error. This chapter discusses ideas from the dynamic systems literature, which focuses on the interplay within and between components of complex systems, such as individuals and their multitiered contexts. This chapter presents three scenarios highlighting knowledge from the dynamic systems literature. These scenarios have implications requiring reconsidering common approaches to explaining the variance associated with change, the conceptualization of effect sizes, and the use of between-person data and analyses to make within-person inferences. The final section provides resources for moving beyond dynamic metaphors and principles, so theories can be translated into testable hypotheses.