Watch: How to mitigate interview bias
2 minutes
Ben Schwencke explains the key strategies for reducing bias in the interview process and building a fairer hiring funnel.
Diversity and inclusion are critical components of a healthy workplace, yet many organisations struggle to put them into practice during hiring. One area where bias consistently creeps in is the interview stage — and often, it goes unnoticed.
Unlike online pre-employment assessments, which are automated and objective, interviews require significant manual input from assessors who may harbour conscious or unconscious biases against candidates from specific groups. These biases can quietly undermine an organisation's diversity objectives while unfairly disadvantaging candidates from certain backgrounds.
In this article, we explore how to reduce interview bias — and why, ultimately, the best approach is to use interviews less for screening and more for what they're actually good at.
The problem with interviews
Interviews are one of the most widely used selection tools in hiring, but also one of the most vulnerable to bias. Research in occupational psychology consistently shows that unstructured interviews have weak predictive validity — meaning they're poor at predicting who will actually perform well in the role — and are highly susceptible to a range of biases, from confirmation bias to affinity bias to the halo effect.
Pro Tip
Even well-intentioned interviewers introduce bias. It's not a failure of character — it's a structural problem with the format itself. The subjective, conversational nature of interviews makes them inherently prone to it.
The honest answer is that you cannot fully eliminate bias from the interview process. You can reduce it through better structure and training, but as long as humans are making judgements about other humans in real time, some degree of bias will remain. This is why smart hiring teams are rethinking how much weight they give to interviews, and when in the process they use them at all.
Put assessments before interviews
The most effective way to reduce the impact of interview bias is to ensure that interviews are used later in the funnel — and only after candidates have been shortlisted on objective data. Pre-employment assessments, such as ability tests and personality questionnaires, are automated, standardised, and free from the personal biases of individual assessors. By using these tools to build your shortlist, you ensure that only candidates who have genuinely demonstrated potential are invited to interview.
When assessments come first, interviews can be used for what they're actually good at: exploring cultural fit, communication style, and the nuanced qualities that structured tests aren't designed to capture.
This approach also reduces the volume of interviews that need to be conducted, which in turn reduces the overall exposure to interviewer bias. Fewer interviews, conducted on a more qualified shortlist, means better decisions and a fairer process for all candidates.
The benefits of assessments in recruitment
Objective, validated, and bias-free — discover how pre-employment assessments improve both the fairness and the quality of your hiring decisions.
Use structured interviews
When interviews do take place, structuring them tightly is the single most effective way to reduce bias. A structured interview uses the same predetermined, job-related questions for every candidate, evaluated against fixed criteria. This removes the variability that allows bias to creep in through impromptu questions or off-topic conversation. Structured interviews also use validated, job-related competencies as their framework, making it far harder for personal impressions or demographic characteristics to influence ratings.
Organisations should never conduct unstructured or conversational-style interviews for high-stakes selection decisions — particularly if they have D&I objectives. The discipline of using a fixed question set and a standardised rating process is non-negotiable.
Provide formal interviewer training
Most interviewers receive no formal training and, as a result, fall back on instinct and personal preference when assessing candidates. Formal training helps interviewers understand the types of bias they're likely to introduce, how those biases manifest, and practical strategies for keeping evaluations objective. This includes training on asking job-relevant questions, scoring against defined criteria, and avoiding discriminatory lines of inquiry.
When interviewers are trained on diversity and inclusion specifically, they can act as ambassadors for these values and spread them throughout the organisation.
The return on investment from interviewer training is considerable — both in terms of quality of hire and in supporting diversity and inclusion goals. It should be treated as an investment rather than a cost.
Use panel interviews
Panel interviews, where multiple interviewers evaluate candidates together, help dilute the impact of any one person's bias. Because different interviewers bring different biases, aggregating their ratings tends to cancel out individual skews — provided the panel itself is diverse. Organisations should be deliberate about who sits on panels, ensuring a range of demographics and perspectives are represented.
As a rule, at least three interviewers on a panel provides enough statistical spread to meaningfully reduce the effect of personal bias. If a sufficiently diverse panel isn't available, increasing the number of panellists helps further.
Panel interviews also create accountability — poor behaviour or unfair treatment of candidates is immediately visible to other panel members, which keeps the process professional and consistent.
Use talent analytics
Talent analytics allows organisations to measure whether bias is actually present in their interview process, rather than assuming it's been addressed. By analysing interview outcomes across different candidate groups, you can identify whether certain interviewers or certain questions are consistently producing biased results. This data makes it possible to intervene with targeted training or process changes rather than applying blanket, generic fixes.
By identifying patterns in interview data, organisations can take targeted steps to mitigate the impact of unconscious bias — rather than guessing at where it might be occurring.
Advanced techniques such as differential item functioning can even identify whether specific interview questions are inherently biased against particular groups, allowing them to be flagged and replaced. This level of rigour demonstrates a genuine commitment to fairness, though it typically requires specialist psychometric or data analytic expertise.
Summary
Interviews are a necessary part of most hiring processes, but they come with real structural limitations. The personal biases of interviewers will always have some impact on outcomes — the goal is to reduce that impact as much as possible. Structuring your interviews, training your interviewers, using diverse panels, and monitoring your data all help. But the most important step is rethinking where interviews sit in the funnel.
Use assessments first to build an objective shortlist. Let the data do the heavy screening. Then bring in interviews to explore the things assessments aren't designed to measure — cultural fit, communication, and candidate potential. This approach makes your process both fairer and more predictive of real-world performance.
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Primary author
Ben Schwencke
Chief psychologist at Test Partnership. MSc in Organisational Psychology with over ten years experience in psychometric testing.
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