INTERVIEWER BIAS:
A bias that occurs when the personal qualities of an interviewer affect how and what data are recorded. For example, an interviewer may consciously or subconsciously gather selective data, influence a subjects responses, or rate responses differently for some individuals vs. others1,2.
Interviewer Bias is sometime used synonymously with Observer Bias. Observer Bias and Interviewer Bias are essential the same, although Interviewer Bias is often used in the context of face-to-face interviews, whereas Observer Bias is often considered a broader term that is relevant to any scenario where data is collected/recorded by an individual for the purposes of research. Also see: Clinician Bias, Assessment Bias, Observer Bias, Information Bias, and Collection Method Related Bias.
References:
1. Porta M, ed. A Dictionary of Epidemiology. Sixth ed. New York, NY: Oxford University Press 2014. (Link to Reference)
2. Griffin BN, Wilson IG. Interviewer bias in medical student selection. Med J Aust. 2010;193(6):343-6. (Link to Reference)