'How long will it take?': an analysis of interview length in the fifth round of the European Social Survey

"The question 'How long will the interview take?' is frequently asked by interviewers during training and by respondents during the initial doorstep interaction. In this paper, we investigate the impact of different interviewers, countries and some respondent characteristics on interview length in the fifth round of the European Social Survey. The results show substantial differences between countries with regard to interview length and reinforce that differences between countries are based on much more than just the differences between languages. The results support the obvious suggestion that fewer applicable questions reduce the interview length. Further, interviewing older respondents takes more time, and the duration also increases if a respondent more frequently asks for clarification. The huge impact of interviewers on interview length is the most remarkable result. In all countries, the difference between interviewers accounts for a significant and substantial part of the variance in interview length. More detailed fieldwork monitoring in each country is necessary in order to understand these differences. The results also clearly illustrate the necessity for investment in training, monitoring and follow-up of interviewers in each country participating in a cross-national survey." (author's abstract