Two different versions of the questionnaire have been fielded, testing differences in wording and answer categories of some questions. The questions differing between the two versions are: WO12, WO14, WO17, WO39 and ETHN. For these questions, separate variables have been created in the dataset, notified by „_A“ for version 1 and „_B“ for version 2.
Additionally, some adaptions of the question formats to the two modes, web and paper, were necessary (for example filter instructions, or open answer instead of selection from a list for nationality).