How can an interviewer’s manner influence answers in a face-to-face survey?

In the context of public opinion polling, an interviewer’s manner and experience level are critical factors that can significantly influence the accuracy of survey data.

Inexperienced interviewers may introduce bias by asking questions in inappropriate ways, which can inadvertently steer a respondent's answer. Furthermore, an interviewer’s conduct can alienate or antagonize participants, potentially leading them to refuse to complete the survey entirely.1

Beyond the direct interaction, interviewer bias can also manifest during the selection process. In quota sampling, where interviewers exercise personal judgment to select respondents, they may subconsciously favor individuals who share their own characteristics, leading to skewed results. Additionally, errors can occur if an interviewer fails to record responses to free-answer questions accurately or lacks the persistence required to locate designated respondents. To mitigate these risks, reputable polling organizations prioritize specialized training to ensure interviewers maintain professional standards and minimize the introduction of human error into the data collection process.21