Table 1 Agency, sampling type, recruitment, fieldwork duration, and sample size of the six surveys
Agency | Sampling | Recruitment | Fieldwork period | Sample size |
|---|---|---|---|---|
NPS-1 | Quota sample | online | 13.09. – 30.09.2016 | 5.002 |
NPS-2 | Quota sample | online | 13.09. – 28.09.2016 | 5.000 |
NPS-3 | Quota sample | online | 13.09. – 16.11.2016 | 5.501 |
NPS-4 | Quota sample | online | 13.09. – 19.09.2016 | 2.877 |
PS-1 | Random sample | offline | 13.09. – 07.10.2016 | 5.001 |
PS-2 | Random sample | offline | 19.04. – 13.06.2017 | 3.065 |