Interviewer variance is examined for 33 interviewers and 3,000 interviews, with age, sex, socioeconomic status, social mobility, and interviewer ratings as key variables. It differs among interview schedule items and is influenced by combinations of sex and age of interviewers and respondents. Selecting interviewers and assigning households-respondents to them is a complex process, and matching interviewers with respondents on “face sheet” characteristics may produce error in some instances while reducing error in others.