EVS (European Values Study) is a large-scale survey on human values and is conducted every nine years since 1981. In the last wave, over 47 countries participated. The research program aims to capture ideas, beliefs, preferences, attitudes, vales and opinions of the population all over Europe. The Swiss National Science Foundation financed the survey waves for Switzerland in 1990, 2008 and 2017. The Swiss sample is composed of a minimum of 1,200 residents 18 years of age and older.
The main difference compared to previous 2008 study relates to the mode of data collection; a parallel mixed mode was allowed for the fifth wave. Data was collected through face to face interviews as well as through autoadministred web-based interviews with paper questionnaires for those who do not have Internet access. Another innovation was that for the individuals in the CAWI group, some were invited to respond to an hour long web survey and others were invited to respond to a shorter version of the questionnaire and an additional survey was proposed to the respondents in order to complete the questionnaire.
The face to face interviews (CAPI):
In the face to face interviews people received an announcement letter. A interviewer visited individuals at least five times at home to invite them to participate in an hours long face to face survey. If no contact could be made, individuals were contacted by telephone in case a telephone number was available. In the end, 673 interviews could be made.
The web-based interviews (CAWI/MAIL):
The second data collection method was a web– and mail-based self-administered interview. The web-based survey was held in two sessions. In the first session individuals were either allocated to the full (original size) survey or to the short survey (around 75% of the questions). In the second sessions only individuals that responded to the short survey were invited to respond to a follow-up questionnaire. 2989 individuals took part in the first session and 1664 individuals responded to the follow-up questionnaire.
A push-to web method was used; in session 1, individuals were invited to participate in a web survey and only with the second reminder a paper questionnaire was added to the mail. In session 2, the respondents that answered previously to a paper questionnaire received with the invitation letter a paper questionnaire; all other respondents received the paper questionnaire with the second reminder.
At the end of the field, 2126 interviews were done on web and 863 were done on paper.
