The K²ID projects collect new data supplementing two large German panel studies: 1) the German Socio-Economic Panel Study (SOEP) in combination with the Families in Germany Study (FiD), and 2) the TwinLife Study. The K2ID-SOEP data comprise information on more than 2,300 German families with young children and about 850 ECEC institutions serving them. The K2ID-Twins samples include 2,020 twins in 1,016 households and information from 485 ECEC institutions.

The following pages will provide details on the samples forming the basis of the K2ID studies including response rates, as well as documentation of the data collection process. Also, interested researchers can learn how to obtain data access.