In comparative studies, there is a natural trade-off between optimizing cross-countries and optimizing within-countries. In deciding the details of the study's design we have given top priority to the first criterion, i.e. maximal comparability. Strategies were chosen that are feasible and promising in all four national contexts simultaneously. The result are strongly harmonized instruments. Each country team, however, implemented the study in their respective country separately.
The study was originally conducted in:
- the Netherlands
Jonsson, SOFI / Stockholm University (now: University of Oxford)
The German team, under the direction of the project's prinicpal investigator Frank Kalter, was responsible for the international coordination of the project and ensured maximum comparability of the study in terms of questionnaire and sampling. Also, the German team manages the cross-country data sets and their public release.
For more information about the different country teams have a look into our section Team.