USE OF FACE-TO-FACE INTERVIEWS IN MIXED MODE DESIGN: THE PROBLEM OF THE ACHIEVED SAMPLE

Two experiments carried out in connection with the European Social Survey (ESS) were aimed at verifying whether the face-to-face interview used in the mixed mode design did indeed produce the aforementioned benefits, compared to the use of face-to-face interviewing in unimode surveys. The idea was to boost the response rate and improve the sample composition. Both experiments were based on the sequential design with elements of the concurrent design. In the former, the face-to-face mode was used in the initial phase, whereas in the latter it was used in the follow-up phase. This mode was combined with self-administered modes, including the most effective of them, i.e. the mail mode. In the experiment aimed at verifying the effectiveness of mixed mode design with face-to-face used first, the ESS main study rounds 6 and 7 were treated as an initial phase.