National Surveys Via Rdd Telephone Interviewing Versus the Internet

In a national field experiment, the same questionnaires were administered simultaneously by RDD telephone interviewing, by the Internet with a probability sample, and by the Internet with a nonprobability sample of people who volunteered to do surveys for money. The probability samples were more representative of the nation than the nonprobability sample in terms of demographics and electoral participation, even after weighting. The nonprobability sample was biased toward being highly engaged in and knowledgeable about the survey's topic (politics). The telephone data manifested more random measurement error, more survey satisficing, and more social desirability response bias than did the Internet data, and…