Study title

The sampling procedures differ from country to country: Probability Sample: Multistage Sample Probability Sample: Simple Random Sample Representative single stage or multi-stage sampling of the adult population of the country 18 years old and older was used for the EVS 2017. Sample size was set as effective sample size: 1200 for countries with population over 2 million, 1000 for countries with population less than 2 million. 8 countries out of 16 deviated from the guidelines and planned with an effective sample size below the set threshold. Germany, Netherlands, Iceland and Switzerland, due to the mixed mode design, allocated only part (50% or more) of the effective sample size to the interviewer-administered mode. Sample design and other relevant information about sampling were reviewed by the EVS-Methodology Group (EVS-MG) and approved prior to contracting of fieldwork agency or starting of data collection. In case of on-field sampling EVS-MG proposed necessary protocols for documentation of the probabilities of selection of each respondent. The sampling was documented using the Sampling Design Form (SDF) delivered by the national teams (see the EVS2017 Methodological Guidelines, Sampling). The SDF includes the description of the sampling frame and each sampling stage as well as the calculation of the planned gross and net sample size to achieve the required effective sample. Additionally, it includes the analytical description of the inclusion probabilities of the sampling design that are used to calculate design weights.