Probing is a common technique that researchers use in interviewer-administered surveys when respondents initially refuse to answer a question or say they “don’t know.” …
However, some researchers have suggested that probing can lead to poor data quality because respondents may guess at an answer when they are asked a knowledge-based question for which there is a verifiably right or wrong answer. Probing also places an additional burden on the interviewer and can increase survey length.
To build on this research, Gallup conducted a series of experiments to study how probing affects responses to objective questions about the respondent as well as responses to attitudinal questions. CONT.
Stephanie Marken & Sofia Kluch, Gallup