What is a longitudinal study?

What is a longitudinal study?

• A. A study that compares individuals of different ages at one point in time.
• B. A case study following a single individual over time.
• C. A study that follows the same individuals over time to observe development.
• D. A cross-sectional survey of multiple groups.

Answer: (C)

Longitudinal study design tracks the same individuals across multiple time points to observe development and change. By following the same people over years or more, researchers can see how early experiences or traits relate to later outcomes, and how a person’s abilities or behavior evolve over time. This approach lets us map developmental trajectories and determine what tends to stay stable versus what changes. A cross-sectional design, in contrast, compares different individuals at one point in time to infer age-related differences, but it can’t show how any particular person develops. A case study can be longitudinal if it follows a single person over time, but the term longitudinal study typically refers to following a group of individuals across multiple time points to study development in a broader sample. A cross-sectional survey of multiple groups is a snapshot across ages and does not track change within the same individuals.

Longitudinal study design tracks the same individuals across multiple time points to observe development and change. By following the same people over years or more, researchers can see how early experiences or traits relate to later outcomes, and how a person’s abilities or behavior evolve over time. This approach lets us map developmental trajectories and determine what tends to stay stable versus what changes.

A cross-sectional design, in contrast, compares different individuals at one point in time to infer age-related differences, but it can’t show how any particular person develops. A case study can be longitudinal if it follows a single person over time, but the term longitudinal study typically refers to following a group of individuals across multiple time points to study development in a broader sample. A cross-sectional survey of multiple groups is a snapshot across ages and does not track change within the same individuals.