Cross-sectional & Longitudinal Research

Cross-sectional: A research design that collects data at one point in time from different groups to compare them.

Longitudinal: A research design that follows the same participants over a long period of time to study changes over time.

Cohort: A group of individuals who share a common characteristic or experience within a defined time period.

Cohort effects: Differences observed between cohorts that arise from their distinct experiences or backgrounds, rather than age or development.

Cross-generational problem: The issue in longitudinal research where findings from one generation may not apply to future generations due to changing contexts or experiences.

Practice effects / test effects: Changes in participants’ performance on repeated tests due to familiarity with the test rather than true changes in ability.

Selective survival: The phenomenon where only certain individuals survive or remain in a study, possibly influencing the results.

Attrition / Selective drop out: When participants drop out of a study over time, potentially biasing results if those who drop out differ significantly from those who remain.

Accelerated longitudinal study: A research design that collects data from multiple cohorts at different stages to simulate a long-term study in a shorter period.

Cross-lagged correlations: A method in longitudinal research that examines the relationship between variables measured at different times to explore cause-and-effect.

Prospective: A research design that follows participants into the future to observe outcomes or effects of certain variables.

Retrospective: A research design that looks backward, gathering data from past events or experiences to understand current conditions or outcomes.