Cross-Sectional, Longitudinal, and Retrospective Designs: General Utility and Threats to Validity

Developmental science is primarily focused on understanding change over time, and the current chapter provides an overview of developmental research designs used to capture intraindividual change and interindividual differences. The general developmental model provides a framework to understand how age, time, and cohort are the central parameters used to measure change and individual differences. The chapter highlights the effectiveness and limitations of cross-sectional, longitudinal, and retrospective research designs, with a focus on methodological challenges such as cohort effects, instrumentation, and the measurement of developmental constructs over time. Emerging designs - including intensive longitudinal and measurement burst designs - are introduced as approaches that can capture dynamic processes and real-time development that can be enhanced with current technological advances. Special attention is given to the application of developmental research designs in marginalized and understudied populations. The advancement of developmental science as a discipline necessitates the use of methodologies and designs that capture the complexity of developmental change within and across multiple cultural and contextual settings.