From Telephone to the Web: The Challenge of Mode of Interview Effects in Public Opinion Polls

Among the most striking trends in the field of survey research in the past two decades is the shift from interviewer-administered to self-administered surveys. … But the results from self-administered and interviewer-administered surveys are sometimes different. This difference is called a mode effect, a difference in responses to a survey question attributable to the mode in which the question is administered. …

Using its nationally representative American Trends Panel, Pew Research Center conducted a large-scale experiment that tested the effects of the mode of survey interview – in this case, a telephone survey with an interviewer vs. a self-administered survey on the Web – on results from a set of 60 questions like those commonly asked by the center’s research programs. This report describes the effort to catalog and evaluate mode effects in public opinion surveys. CONT.