Longitudinal Versus Cross-Sectional Design, Analysis

Longitudinal and cross-sectional designs are two common research designs for answering theoretical questions about age or maturation effects. A longitudinal design is one that takes repeated measurements of the same sample of participants over time. A cross-sectional design is one that takes a single measurement of several cohorts (or age groups) of participants. These designs are especially useful for conditions that cannot be experimentally manipulated for practical or ethical reasons (e.g., disease prevalence, assessing parenting effects, risky behavior). Longitudinal and cross-sectional designs each have advantages and disadvantages for researchers, and some hybrid designs have been developed to maximize the advantages and limit the disadvantages of each. This entry identifies key features, advantages, and disadvantages of longitudinal and cross-sectional research designs in life-span human development and ...