Why you should only be using structured interviews

Most recently I have been asked by the companies through which I contract to assess a candidate’s personality based on a personality questionnaire together with their fit for a particular role. Nothing new here as best practice recommends using a psychometric to measure a candidates’ personality and then using an interview to verify and expand on those personality ratings. However, I have found an increasing propensity to focus on personality over fit for role resulting in lengthy and complex interviews often filled with psychobabble.  In actual fact there is a fairly low correlation between interview ratings and self report measures of personality so we need to come up with a user friendly way of testing personality and fit for role (which I call performance) at the same time.

Research by Professor Levashina and colleagues has found that people are more accurate when judging someone else’s personality when we are looking at more observable traits such as how extraverted or conscientious that person is. Perhaps this is because it is easier to collect data on these constructs or it could be because it is easier for us to imagine a link between extraversion, for instance, and how effective that individual is likely to be working in a team.

The best way to verify and expand on personality and at the same time provide a performance dimension is to ask questions that are designed to measure the on-the-job behaviors related to a specific personality trait. For example, asking the candidate to, “Tell me about a time when you had a work-related disagreement with a colleague. How did you resolve it?” to measure Agreeableness. Or measuring Conscientiousness by asking the candidates how they set goals or meet deadlines enables interviewers to verify the personality constructs but in a relevant context. Compare this with “Tell me who was your greatest influence growing up?” which might give an insight to an individual’s motivation and self reflection but nothing about how that impacts their work performance.

The interview structure that best assesses personality is a structured interview.

Evidence from thousands of interviews tell us that a structured interview is more reliable, valid, and less discriminatory than an unstructured interview.

So how do they differ?

An unstructured interview is the typical job interview: Tell me about yourself, What’s your biggest weakness, Which superhero would you be? etc. When asked to assess for personality, it is very easy to fall in to the trap of asking these rather subjective questions.

A structured interview asks questions specifically designed to assess job-related knowledge and skills, asks the same questions to all candidates, rates every answer to each question using a quantitative rating scale, and generally involves training the interviewer on how to do this properly.

Why does a structured interview lead to better hiring? Simply, structured interviews reduce error: it both reduces interviewer bias and it reduces the ability of candidates to fake their answers during an interview.

How to do it:

The best way to measure personality with an interview involves:

  1. understanding the demands of the role
  2. carefully designing the best job-related questions to ask
  3. systematically collecting the data
  4. using quantitative ratings to make your hiring decisions.


So why don’t more people do this? It’s a lot more work and requires training and expertise. If you have any concerns about your hiring and assessment decisions, contact Chiswick Consulting and we’d be pleased to talk it through.