Longitudinal Cross-Sectional Research — Cohort-Sequential Design

Longitudinal cross-sectional research — also called cohort-sequential or accelerated longitudinal design — simultaneously follows multiple age cohorts over time, combining the depth of longitudinal tracking with the age-range efficiency of cross-sectional sampling. By overlapping cohorts at successive waves, researchers can disentangle age effects, cohort effects, and period effects far more rigorously than either pure design allows, and can compress the calendar time needed to study development across a wide age span.