What is Interviewer Error? | Market Research Firm Upstate NY

Virtually all types of marketing research methodologies incur some type of bias. Whether it be sequence bias, the halo effect, acquiescence bias, or self-selection bias the options are endless. All have an impact on your data quality and are often an accepted limitation in the industry. Another type of bias is often called interviewer error.

What is Interviewer Error? | Market Research Firm Upstate NY


What is interviewer error?

Interviewer error is a form of bias in which the interviewer administering the survey in-person, by phone, or through chat impacts choice of responses through the interaction. This can come in the form of word choices, attitude, demeanor, or facial expressions. Basically anything during the research conversation that may impact the responses positively or negatively can be labeled interviewer error.

Here are some examples of interviewer error:

  • The telephone interviewer listens to a recent bad experience at hospital recapped by a respondent through an open-end. There is a follow-up question which asks overall satisfaction with the hospital on a most recent visit on a 1 to 5 scale in which the interviewee states, "it sounds like your recent trip didn't go well, so using a scale of 1 to 5 where "5" indicates very satisfied and "1" indicates not at all satisfied, how satisfied are you with your most recent experience at Hospital ABC?" Although the respondent offered negative feedback through prior comments, the interviewee should never lead the respondent towards a choice before reading the question.

  • The telephone interviewer is overly enthusiastic throughout the call. From start to finish the interviewer is upbeat, encouraging good and positive feedback throughout. Unconsciously, as a result, his/her attitude changes the attitude of the respondent to rate the aspects of the customer experience more favorably than normal circumstances.

  • Some other forms of interviewer error are assumption-based. For instance, if a person guesses an age range of the respondent. Another assumption could be an interviewer assuming that if the person answers a cell phone, he/she is the owner of the phone.

As a research company conducting a lot of voice-of-customer (VoC) telephone interviews, this always remains top-of-mind. In order to collect unbiased and accurate data points, our company needs to make sure that we do not lead the respondent and remain neutral. Keeping an objective mindset when conducting interviews is key. Ensuring projects include a variety of interviewers as well as using CATI systems helps mitigate interviewer error. Using CATI or a pre-written scripts helps prevent the interviewing from stepping outside of the interview process structure.


Drive Research is a market research firm in Upstate, NY. Interested in executive phone interviews? Call us at 315-303-2040 or email us at info@driveresearch.com.

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