Longitudinal approaches allow for the articulation of (non)linear and dynamic processes that are at the heart of many communication theories. Despite recent advances in longitudinal data collection (e.g., ecological momentary assessments, mobile tracking) that can capture the dynamic processes described by communication theory, the availability and application of longitudinal analytic methods to model these processes remains a challenge. In this working group, we will discuss the alignment of theory and longitudinal analytic techniques as well as identify current methodological constraints that impede testing theory-driven communication processes. The goal of this working group is to pinpoint directions for future longitudinal methodological development that will have the broadest impact on the field.