Longitudinal studies provide an excellent research learning environment for trainees

Compared to experimental studies that require complex infrastructures such as laboratories or clinical trials at multiple centers, studies using a longitudinal cohort (an observational research method in which data is gathered for the same participants repeatedly over a period of time) could be a good alternative for investigators as they begin their early research careers.

source https://www.lifetechnology.com/blogs/life-technology-news-blog/longitudinal-studies-provide-an-excellent-research-learning-environment-for-trainees