A multi-epoch study involves conducting research or data collection over multiple time periods or epochs. This approach allows researchers to observe changes or patterns over time and can provide valuable insights into trends, developments, or shifts in a particular phenomenon or topic. Multi-epoch studies are often used in longitudinal research, where data is gathered from the same group of subjects at several points in time. This approach can help to track changes in behavior, attitudes, or outcomes over time and can contribute to a more comprehensive understanding of complex processes or relationships.