The interviewer contribution to variability in response times in face-to-face interview surveys

Survey researchers have consistently found that interviewers make a small but systematic contribution to variability in response times. However, we know little about what the characteristics of interviewers are that lead to this effect. In this study, we address this gap in understanding by linking item-level response times from wave 3 of the UK Household Longitudinal Survey (UKHLS) to data from an independently conducted survey of interviewers. The linked data file contains over three million records and has a complex, hierarchical structure with response latencies nested within respondents and questions, which are themselves nested within interviewers and areas. We propose the use of a cross-classified mixed-effects location scale model to allow for the decomposition of the joint effects on response times of interviewers, areas, questions, and respondents. We evaluate how interviewer demographic characteristics, personality, and attitudes to surveys and to interviewing affect the length of response latencies and present a new method for producing interviewer-specific intra-class correlations of response times. Hence, the study makes both methodological and substantive contributions to the investigation of response times