Separating Interviewer and Sampling-Point Effects

Abstract

Data used in nationwide face-to-face surveys are almost always collected in multistage cluster samples. The relative homogeneity of the clusters selected in this way can lead to design effects at the sampling stage. Interviewers can further homogenize answers within the small geographic clusters that form the sampling points. The study presented here was designed to distinguish between interviewer effects and sampling-point effects using interpenetrated samples for conducting a nationwide survey on fear of crime. Even though one might, given the homogeneity of neighborhoods, assume that sampling-point effects would be especially strong for questions related to fear of crime in one's neighborhood, we found that, for most items, the interviewer was responsible for a greater share of the homogenizing effect than was the spatial clustering. This result can be understood if we recognize that these questions are part of a larger class of survey questions whose subject matter is either unfamiliar to the respondent or otherwise not well anchored in the mind of the respondent. These questions permit differing interpretations to be elicited by the interviewer.