Longitudinal research involves studying individuals or groups over an extended period of time, often years or even decades. This type of research allows researchers to observe how variables or behaviors change and develop over time, providing insight into the long-term effects of certain factors. Longitudinal studies are especially useful for tracking individual development, understanding trends and patterns, and assessing the impact of interventions or treatments over time. This research design typically involves collecting data at multiple time points, allowing for the analysis of changes and patterns over time.