General population surveys target the entire adult populations of participating countries, where, in many advanced societies, older respondents constitute an ever increasing share. Reflecting these processes, in the European Social Survey (ESS), the proportion of older respondents has been increasing.22 Prior research has found that older respondents are more often assessed by interviewers as having problems with understanding survey questions. This has been attributed to older respondents’ lower cognitive performance resulting in lower quality responses. While researchers recognize the social character of the face-to-face interview situation, till now, analyses of the links between age and data quality have focused on characteristics of the respondent while largely ignoring the characteristics and active role of the interviewer. One possible reason for this is that data on interviewers’ characteristics in many publicly available datasets are either lacking or very limited. Ignoring the role of the interviewer may also be related to the wider tendency to treat survey (quantitative, in general) data as “objective”, despite methodological evidence to the contrary.