What a job interview actually measures, and what it misses
There is an experience many people have without ever putting words to it: leaving an interview knowing you were worse than yourself. Not that you failed, but that you failed to show what you can do. The question arrived sideways, the answer came out muddled, and it took twenty minutes to find the thread again.
The instinct is to conclude that you handle pressure badly. Possibly. But there is another reading, and it is more useful: the unstructured interview is a poor measuring instrument, and you have just experienced that first hand.
An unstructured interview mostly measures interview comfort
This is what work psychology has established for a long time. The unstructured interview, where the recruiter improvises questions and trusts an overall impression, has mediocre predictive validity. The structured interview, where every candidate gets the same questions scored against a grid, predicts actual job performance considerably better.
A doctoral thesis under way at the Université de Lorraine, by Sophie Poirson, works on exactly this question and on what structured interviews change in terms of fairness: reducing cognitive bias in recruitment. Its abstract also raises a useful caveat: a given employer cannot assume that the average of a study applies to their own organisation.
Put differently, the gap between what an interview measures and what you are worth at work is not an individual accident. It is a known property of the tool.
Why that gap is wider for some people
The mechanism is concrete. Answering an unexpected open question draws on working memory: hold the question, find an example, structure it, deliver it, all while monitoring your own performance.
And working memory is the first thing stress degrades. In a Welcome to the Jungle piece on stress in interviews, that mechanism is named explicitly, and an HR director points out that factors as trivial as a transport problem artificially shift a candidate’s performance.
For people whose working memory is particularly sensitive to pressure, which covers many ADHD-type ways of functioning without being a rule or a diagnosis, the unstructured interview is not measuring a professional skill. It measures a talent for improvising live, which often has nothing to do with the job.
There is an exception that proves it. Those same people frequently do very well on a practical exercise, a written scenario, or a conversation about work they have genuinely done. The issue is not competence, it is format.
Three requests that change the format
You have more room than you think, provided you ask before the interview rather than during it.
The question topics, in advance. Not the exact wording, but the subjects that will be covered. This is an ordinary request, and many recruiters accept it because it saves them time too. It turns an improvised recall exercise into a prepared conversation, which is precisely what the interview claims to assess.
The format and its length. How many people, how long, a conversation or a work scenario. Knowing you will have forty minutes with two interviewers changes how you prepare, and removes a good share of the uncertainty load.
Something concrete to discuss. Offer to start from real work (a project, a case, a file you handled) instead of answering general questions. You move the assessment onto ground where you are good, and you give the recruiter far better information than your fluency out loud.
None of these requests obliges you to explain why you are making them. That point matters, and we go into it in our article on talking about your constraints in an interview: describing a format need does not require exposing what drives it.
What a refusal tells you
Sometimes these requests are turned down, and the information is valuable.
An employer who refuses to say in advance what will be discussed is attached to the element of surprise. They therefore consider reaction to the unexpected to be the core of the assessment. Sometimes legitimately, for a role where that is the job. Often out of habit. In the second case, you have just learned something about how this organisation judges people, and probably about how it will manage them.
It is the same subject seen from the other side as in our article on hiring for attitude or skills. And if the underlying question is which environments suit you, that is what identifying a compatible work environment covers.
An interview remains an imperfect filter, and preparing for one guarantees nothing. But you are not obliged to accept a format that measures something other than what you can do.
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