The employment interview is one of the most widely used recruitment methods and as such has been extensively researched. A consistent finding from this research is that structured interviews are more reliable and valid than their unstructured counterparts*. Three key reasons are discussed which highlight why this is the case.
What is structure?
A structured interview is defined as one which has interview questions written against a framework (e.g. competencies) and a defined rating guide. Each candidate is asked the same questions in the same order and is scored against the same objective rating guide in a structured interview. Unstructured interviews give complete latitude to the interviewer with the content of questions (often interviewers choose to question about factors which are not job relevant) and the scoring methodology (typically no formal scoring is utilised).
Why does structure matter?
1) Validity- structuring your interview increases its validity (i.e. you are most likely to select people who will perform well in the job)
Using designed, consistent questions and scoring guides, which link to key job success factors, means that those candidates who score highly in the interview will go on to perform better in the job than those that don’t score so well. Unstructured interviews typically use questions with little grounding in job success factors and scoring is subjective, and flawed. These types of interviews do not discriminate between candidates who will do well/poorly in the role as relevant skills have not been tested.
2) Interviewer Bias- structure decreases the effect of interviewer bias
As human beings, we are all subject to biases- both conscious and unconscious. Allowing biases to influence our judgement of a candidate during an interview has been proven to reduce the effectiveness of a hiring decision **. Structuring an interview- both in terms of the questions and the scoring criteria, whilst not failproof in eliminating bias completely, will reduce the impact of this bias. This is because an interviewer is not given latitude to explore non-job-relevant areas with candidates and is asked to judge each candidate against set, well-defined, job-relevant criteria.
3) Legal Defensibility– structure increases the legal defensibility of your interview process
With any recruitment decision, the onus is on an organisation to be able to prove that the process and methods used were fair and did not directly or indirectly discriminate against candidates. With an unstructured interview process, hiring decisions are often made on factors which are not relevant to the job and candidates are treated differently, unequally and unfairly. Decisions made using a structured interview process which is consistent and where questions and scoring are based on strict job requirements are much more defendable.
Given the above, it is surprising that the use of unstructured interviews continues to be so prevalent.
*Levashina, Personnel Psychology, 2014 ** Harvard Business Review 2016