1 National Surveys Via RDD Telephone Interviewing vs. the Internet: Comparing Sample Representativeness and Response Quality

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 non-probability sample of people who volunteered to do surveys for money. The probability samples were more representative of the nation than the non-probability sample in terms of demographics and electoral participation, even after weighting. The non-probability 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 the probability Internet sample manifested more random error and satisficing than did the volunteer Internet sample. Practice at completing surveys increased reporting accuracy among the probability Internet sample, and deciding only to do surveys of on topics of personal interest enhanced reporting accuracy in th