How to Minimize Bias During Interviews

Have you ever taken a favorable liking to one individual over another based on their interests? It happens a lot, and that’s how most friendships start. However, this has no place in a customer interview.

Having a clear understanding of your business’s customer persona is integral to your success. The more comprehensive knowledge you have captured to understand your target audience, the better personalization, branding, advertising, and overall experience the buyer will have. 

An effective way to understand your clients is by conducting interviews. Physically speaking to your prospects promotes higher levels of engagement, truthfulness, and data quality. However, it can sometimes be challenging to achieve this accurately as biased opinions can form. 

That’s why we asked the researchers from STAM Research to provide insight on how to best mitigate these biases.

What types of interview bias occur? 

Being biased is human nature and is split into two categories: conscious and unconscious bias. To visualize the differences between these, see the table below: 

Conscious Bias

Unconscious Bias

Refers to the biased attitude that you’re aware of and can control

Refers to the biased attitude that operates outside of your awareness and control

We know we’re being biased and typically do this intentionally

We might not know we’re holding biased attitudes toward something

Sometimes there can be malicious intent

Most of the time, there’s no malicious intent

It can be observed and solved

It can be challenging to monitor and solve


Although both can affect a customer interview and data quality, unconscious bias is the primary culprit. That’s because unconscious bias is an attitude that occurs outside of your awareness and control. Because of this, it’s remarkably difficult not to form biased opinions that’ll affect the interview.

Why is customer interview bias a problem? 

Being biased can lead to discrepancies and inaccurate data, which is not ideal when developing research on a customer persona. Some problems businesses encounter from being biased in their customer interviews: 

  • Customer personas – 93% of companies that exceed lead and revenue goals reportedly segment their databases into buyer personas. The importance of understanding a target audience can have a dramatic effect on a company’s performance. Without this, you cannot build effective strategies targeted toward a specific set of individuals. 
  • Customer demands – In America, a company loses 23 to 30 percent of its existing clients yearly from a lack of customer loyalty. If you don’t listen to your customers’ demands, you can’t fulfill their needs. This means poorer experiences for them and a decreased perception of the value of your goods or services. 
  • Product development – Expanding a business and developing new products is excellent. But it’s only possible when genuinely understanding the customer persona. Not having adequate information can result in poor performance in all stages of product development, from concept to release. 

Being biased can have a significant effect on a business. From doing this, you won’t be able to obtain the information necessary to effectively pursue a customer persona.  

Because being biased during an interview can alter the outcome, there isn’t enough solidified or accurate data on a customer persona. When this occurs, it makes other business practices remarkably hard when considering the buyer. 

How to reduce common types of interview bias

Author and entrepreneur Steli Efti once said, “whichever company understands the customer best will eventually have them as customers.” It’s a powerful quote and something all businesses need to remember when building customer personas. 

As we know, customer interviews play a considerable role in developing buyer personas. Lessening or eliminating interview bias is essential to ensuring optimal accuracy and worthiness. To make these interviews effective, familiarizing yourself with the following types of bias is mandatory. 

Confirmation bias 

Confirmation bias is one of the most destructive unconscious thought processes during a customer interview. We build opinions about specific subjects throughout our lives that are good or bad. As a result, we’re developing confirmation bias, which is the tendency to search, favor, interpret, or recall information to support our personal beliefs. 

It affects customer interviews because you could intake information differently based on various factors. For instance, a customer could express concerns, but you justify the discussion into something you want to hear. 

To reduce this from occurring and potentially ruining the results, you’ll want to perform the following: 

  • Clear your mind before every interview to ensure stereotyping or past events don’t force you into confirmation bias. 
  • Have goals in mind and develop a plan of action that isn’t impacted by your emotions. 
  • Think out loud and try to dive deeper into the discussion so you can fully grasp the customer’s conversation. 

Affect heuristics

Another common type of bias in customer interviews is affect heuristics. This follows a similar concept to the above, but with slight differences. Instead of interpreting data based on personal beliefs, affect heuristics relies heavily on emotion. 

During the customer interview, you can develop emotions about particular topics and conclude something without factual information. When this happens, the interviews will lack the same approach. That’s because emotions could overpower the conversations and steer them in a different direction compared to the others. 

To obtain fair results, the interviews must be similar. Having a better “bond” with one customer over another could result in them providing data that isn’t necessarily accurate. To reduce this, consider the following practices: 

  • Separate your emotions from the interview and guarantee every customer is approached in the same manner.  
  • Only base conclusions on concrete data; don’t manipulate conversations into something you wanted to hear. 
  • Always remember your goals and the fact that not everybody will provide you with the “expected” answers. 

Similarity attraction bias

Have you ever taken a favorable liking to  one individual over another based on their interests? It happens a lot, and that’s how most friendships start. However, this has no place in a customer interview. 

By allowing similarity attraction bias, you’re not giving customers an equal opportunity to express their thoughts. Instead, specific customers you like might be approached differently, affecting the results. 

To keep this from happening,  build a mental bridge to separate your personal life and the interview. Doing this will guarantee you don’t encounter inaccurate results from taking a particular liking to somebody. To minimize the effects of similarity attraction bias, you should:

  • Create an emotional barrier between your personal feelings and the goals of the interview. 
  • Stick to a structured plan and be mindful if you begin speaking off topic (you might pivot the conversion unknowingly).
  • Remain consistent in your approach to each customer, regardless of their interests or how much you like or dislike them.


At this point, you should understand how to conduct yourself professionally while minimizing these three biases during customer research interviews. Otherwise, even small changes can dramatically affect results, which could cause a domino effect in multiple performance areas of your study. 

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