What type of bias occurs due to the refusal to participate of those approached by an interviewer?

The type of bias that occurs when individuals approached by an interviewer refuse to participate is known as nonresponse bias. This bias arises when the opinions or behaviors of those who chose to participate may differ significantly from those who did not. As a result, the collected data may not accurately represent the overall population, leading to skewed results.

For example, if a survey is conducted to understand public opinion on a controversial topic, individuals who feel strongly against the topic might be more likely to refuse participation than those who are indifferent. This can create an unbalanced view in the data, as the responses gathered will primarily reflect the perspectives of those who chose to participate, potentially ignoring important insights from non-participants.

By identifying nonresponse bias, analysts can consider methods to mitigate its effects, such as analyzing demographic differences between respondents and non-respondents or employing strategies to encourage participation that might yield a more representative sample.