Data used in nationwide face-to-face surveys are 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 sampling points. The study presented here was designed to separate 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