What type of research collects data from the same group of individuals over time?

Longitudinal research is a method that involves collecting data from the same group of individuals at multiple time points. This design allows researchers to track changes and developments over time, providing insights into how variables evolve and potentially identifying causal relationships. By observing the same individuals repeatedly, researchers can analyze trends and patterns, which offers a comprehensive view of the phenomena being studied. This type of research is particularly valuable in fields like psychology, sociology, and education, where understanding changes over time can lead to more effective interventions and policies.

In contrast, cross-sectional research involves examining data from a population or a representative subset at one specific point in time, which does not allow for tracking changes. Quasi-experimental research typically focuses on evaluating the effects of interventions without random assignment, and mixed-method research combines qualitative and quantitative approaches but doesn’t specifically emphasize repeated measures over time. Thus, longitudinal research is distinctive for its focus on the same group and its ability to inform over time.