The Science of Interviewing

5 Best Practices to Improve Your Interview Process

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Selecting the right candidate is really hard. And small mistakes can mean the difference between success and failure. There is no shortage of good advice from around the world, but what does science say?

At Swyg, we spend a lot of time researching how to get interviewing right and we want to share some of our insights that you can implement in your own hiring process.

Why do we care so much about interviewing? Because, real human interaction (when done right) remains the most reliable selection tool backed by science.

The most effective ways to identify the right people

Evaluating the validity of selection methods is a challenge. There is a lack of studies that compare candidates' scores in an assessment (like a skills test or interview) to job performance of those candidates.

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One of the major results in the scientific literature is the work of Schmidt and Hunter [1] which shows that interviews, work samples, and knowledge tests are among the most effective tools in assessing talent.
These findings demonstrate that interviews are objectively effective. But just as importantly, there is a prevailing belief in the industry that interviewing works [2] and as a result it is a method widely used.

Interestingly, job experience and age are poor predictors of future performance.

Next, we’ll go over a few specific ways you can improve your own interview process.

Leverage the Power of Structured Interviews

Why: Structure reduces biases and ensures all candidates are treated equally.

Structure is the single most important factor in making interviews effective [3].

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A Structured interview consists of a standardised set of questions that bases the candidate evaluation on a predefined criteria (e.g., this candidate obtained 4 out of 5 for “Planning and organisation"). In highly structured interviews, all candidates are asked the same questions and are rated on the same scale.

This yields major benefits:

  1. Better decision making process - the uniform treatment of candidates makes it possible to compare them under the same conditions and in relation to the same requirements, and thus better evaluate the merits of each. Structure also reduces noise due to inconsistent interviewing conditions and reduced racial bias [4].
  2. Easier evaluation. Rating all candidates on the same criteria and on a numerical scale makes it a lot easier (and faster) to compare candidates. Moreover the allocated time per interview is easier to control when you have a solid structure [5].

Being transparent and fair is the impression you would like to leave each candidate with, right?

Ask the right questions

Ask competency based questions (i.e. related to the job) that probe knowledge and use situational/behavioural question formats.

  1. Knowledge based questions - ask a candidate about work-related concepts and their relevance to the job (for a book-keeper job “What is double-entry book-keeping and why is it important?”)
  2. Situational interview question [6] - present the applicants with a hypothetical job-related situation ("What would your approach be to solve a persisting problem in our back-end system?").
  3. A behaviour description interview question - ask the applicants to describe a real situation from their past relevant to the job for which they are applying. (“Tell me about a recent challenge you have had with a client”)

By comparison, open ended questions like “Tell me about yourself” or self-evaluation questions like “What are your strengths?” are much less effective [5].

Avoid overwhelming your Interviewers

Why: Interviewer fatigue leads to poor decision making based on gut feelings.

Often interviewers become fatigued during the process of listening to candidate after candidate - the times in which they are paying most attention to candidates are at the beginning and end of interviews [7]. After the fourth candidate, the amount of information the interviewer is trying to sort becomes overwhelming and they revert to making snap decisions based on gut feelings [8]. This is specifically tough with high-volume roles (graduate, internship programs, customer support).

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On the flip side, there is also a documented phenomenon related to Respondent fatigue which impacts the quality of the provided information after being exposed to lengthy processes such as tests or interviews.

Organizations may benefit from limiting the number of interviews an interviewer conducts in immediate succession to around 4.

Random Ordering of Candidates

Why: Primacy & Recency bias affect candidates that are interviewed first and last.

People usually talk to the most exciting candidates first. Why is this a bad practice?The first impressions are particularly influential because interviewers engage in hypothesis confirmation strategies that are designed to confirm their initial impressions. Interviewers with positive first impressions of an applicant tell them more about the role and the company [9].

The primacy effect comes into play when one is the first candidate in an interview. Interviewing first allows the individual to give the interviewers an impression that sets a precedent for all interviews after, and often creates an impacting memory.

The recency effect affects an interviewee that is last in the interview process. This individual will make a lasting impression on the interviewers because they are the most recent candidate, which means they will most likely be remembered best out of all the candidates [10].

A first step to mitigating this effect is to be aware of it, and not to assign more value to these individuals just because they may be easier to remember. However, there are more systematic ways to overcome these problems.

More Interviews with Shorter Duration

Why: Getting multiple perspectives reduces the effects of errors made by a single interviewer.

As humans, we all bring some bias to our perception of the world. It’s almost impossible for a single person to make a completely objective assessment of another person.

Because of that, one of the best ways to improve the reliability of an interview process is to get multiple reviewers to evaluate each candidate (even if the total amount of time spent with a candidate is not increased). It makes intuitive sense that a process with multiple reviewers can address the primacy and fatigue problems we mentioned earlier [11].

The science shows that multiple shorter interviews (e.g. 10 minutes per interview) conducted by different interviewers yield superior reliability compared to a single interviewer conducting a longer interview [12].

It’s important to make sure the interviewers are independent: having two interviewers conduct two individual interviews is superior to having two interviewers conduct an interview together.


Our Science-based tips for your hiring process:

  1. Ensure you create a structured interview process with competency based questions.
  2. Ask competency-based questions about knowledge and experience.
  3. Consider the amount of interviews you organise per day and per week to avoid a potential negative impact from interview fatigue - both for you and your candidates.
  4. Be aware of the judgement calls you make as a result of the primacy and recency effects.
  5. Conduct multiple short interviews instead of one longer one.

We can help

Implementing even a few of these suggestions consistently can be hard and even impossible for a single person. We built the Swyg platform to implement these (and several more) best-practices by design.

For now, just bookmark this article so you can refer to these resources when you’re hiring.


[1] Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological bulletin, 124(2), 262. (pdf)

[2] Klehe et al (2010). Reasons for being selective when choosing personnel selection procedure (pdf)

[3] Huffcutt et al (2014). Moving Forward Indirectly: Reanalyzing the validity of employment interviews with indirect range restriction methodology (pdf)

[4] Huffcutt et al. (2001). Assessment of Psychological constructs measured in employment interviews (pdf)

[5] Pettersen, Durivage (2008). The Structured Interview, Enhancing Staff Selection (pdf)

[6] Latham, Saari, Pursell, & Campion, (1980). The Situational interview (pdf)

[7] Zackal, J. (2015, May 5). Is It Better to Interview First or Last?

[8] Frieder, Van Iddekinge, Raymark (2015). How quickly do interviewers reach decisions? An examination of interviewers' decision‐making time across applicants

[9] Dougherty, Turban, & Callender (1994). Confirming first impressions in the employment interview. A field study of interviewer behavior (pdf)

[10] Shaheen, J. (2010). The Recency and Primacy Effects in the Talent Acquisition Process

[11] Kluemper, D. H., Rosen, P. A., & Mossholder, K. W. (2012). Social networking websites, personality ratings, and the organizational context: More than meets the eye? 1. Journal of Applied Social Psychology, 42(5), 1143-1172. (pdf)

[12] Kreiter, C. D., Yin, P., Solow, C., & Brennan, R. L. (2004). Investigating the reliability of the medical school admissions interview. Advances in Health Sciences Education, 9(2), 147-159. (pdf)

Some Lighter Reading

How to Take the Bias Out of Interviews

The Structured Interview, Enhancing Staff Selection

8 Cognitive biases that Interviewers should know

The Gitlab Guide to Interviewing

OPM Guide to Structured Interviews

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