Commentary: Ecology momentary assessment as a tool for understanding dynamic patterns in child and adolescent health and development - reflections on Russell and Gajos (2020).

Ecological momentary assessment (EMA) has served as a methodological tool across subdisciplines in psychology, shedding light on family, personality, and affective processes, and physical and mental health. In their review, Russell and Gajos demonstrate how EMA can overcome several limitations of traditional methods in developmental psychopathology to answer questions about mental and behavioral health in youth. They also provide thoughtful future directions on integrating sensor technology, advancing modeling techniques for temporally dense data, and employing EMA for delivering interventions. This commentary similarly advocates for the use of EMA but extends Russell and Gajos's review by emphasizing EMA's utility for understanding and revealing dynamic changes and processes along micro timescales that have relevance for youth's health and development. We discuss how EMA can be especially fruitful for advancing theory and practice when administered in bursts and when combined with traditional assessments and longer-term longitudinal designs. Because such studies are resource-intensive, we also consider how extant EMA studies can be leveraged and subjected to meta- and mega-analytic techniques to inform theories and future EMA designs. We conclude that EMA is a promising tool for elucidating dynamic fluctuations in experiences and intra- and interpersonal processes that contribute to child and adolescent development and risk.