In a longitudinal study data has been collected on the same observation over time. Since the repeated measures taken on the same observations are not independent from each other this is a type of multilevel data and special care needs to be taken during the analysis to account for this non-independence. These types of data are not only encountered in social sciences but in many different fields e.g. when researchers observe plants/insects/agricultural plots repeatedly over time. The workshop will introduce different approaches possible to analyze longitudinal data and the challenges that such a data analysis can present.