Causes of Mode Effects: Separating out Interviewer and Stimulus Effects in Comparisons of Face-to-Face and Telephone Surveys

We identify the causes of mode effects in comparisons of face-to-face and telephone surveys, by testing for differences in the extent of satisficing and social desirability bias due to differences in the stimulus (visual vs. aural presentation of response options) and the presence vs. absence of the interviewer. The stimulus did not lead to differential measurement error; the presence or absence of the interviewer however did. Telephone respondents were far more likely to give socially desirable responses than face-to-face respondents when the stimulus was the same for both modes.