In 2012, the European Social Survey carried out a mixed-mode experiment, with the aim of investigating the feasibility of using a mixed-mode of data collection process that results in better coverage of the population and lower costs than the traditional face-to-face only data collection methodology. Estonia is one of the countries with highest Internet access and usage in Europe, where 70% of Estonians have internet access at home and the proportion of internet users is highest among those 20-40 years old. Young respondents are the main source of non-contacts and refusals in Estonian surveys, and it was expected that they would be more likely to participate in a web survey and an rise overall response rate. A sequential mixed-mode design was implemented with 927 sample units. All participants were first invited by mail to complete a survey online and nonrespondents were contacted later for a face-to-face interview. The timing, set-up, wording of questionnaires, fieldwork agency, interviewers and all other aspects of the mixed-mode survey were kept very similar to the main face-to-face ESS survey. 355 respondents completed online survey and 223 questionnaires were completed in face-to-face mode.
This paper analyzes mixed mode survey response rates, non-response structures and quality of same ESS repeated questions in comparison with main ESS data. Face- to – face mixed mode respondents had an additional question about reasons why they did not respond to online call, what will be analyzed. Quality of the mixed-mode survey outcome will be compared to the face-to-face ESS main survey in terms of costs, timing and other additional challenges.