The GESIS Panel is a social science data infrastructure for both primary and secondary researchers in Germany. It consists of two samples: the GESIS Panel.pop and the GESIS Panel.dbd. The GESIS Panel.dbd includes Longitudinal Core Studies and externally submitted studies. The GESIS Panel.pop Longitudinal Core Studies aims to measure frequently demanded characteristics beyond demographics, as well as to assess and control for data quality (i.e., different sources of survey errors) by measuring concepts such as survey participation evaluations, survey mode habits and preferences, and by including selected items from other benchmark surveys. In 2013, the study recruited approximately 4,900 panellists. Refreshment samples were added in 2016, 2018, 2021, and 2023, resulting in a total of over 5,400 panellists. Participants include German-speaking individuals aged 18 years or older at the time of recruitment, with permanent residence in Germany. Between 2014 and 2020, the GESIS Panel waves were conducted every two months. Since 2021, the waves have taken place every three months.