Extended definition
The unstructured interview is the historical default — and still, in most companies, the actual default despite decades of evidence against it. Each interviewer follows their own line of questioning, candidates get asked different things, and the debrief turns on personal impressions rather than scored evidence.
Unstructured interviews are popular because they feel natural and let interviewers “go where the conversation goes.” That same flexibility is why they predict job performance poorly: different questions, different standards, different decisions for similar candidates.
Almost every modern interviewing improvement — structured, behavioural, competency-based, calibrated — is a deliberate move away from the unstructured baseline.
Key elements of an unstructured interview
What makes an interview unstructured isn’t the absence of conversation — structured interviews are still conversational — but the absence of standardisation. The defining features:
- No predefined question list — The interviewer goes in with a CV and asks what feels relevant. Two candidates for the same role get asked different questions, often different topics entirely.
- No scoring rubric — Assessment is impressionistic — “good fit,” “not quite right,” “I liked them.” Evidence is anecdotal rather than scored against criteria.
- Interviewer variability — What gets asked depends on who’s asking. A technical interviewer probes technical depth; a manager probes management style; a peer talks about working style. Each interview becomes a different test.
- Decision by composite gut feel — The hiring decision aggregates impressions, not scored evidence. The loudest or most senior voice often anchors the room.
There are legitimate uses for unstructured conversation — early relationship-building with passive candidates, informal coffee chats with prospective talent — but as the formal assessment, unstructured interviews under-perform reliably. The research consensus is settled: structured interviews predict job performance roughly twice as well. Companies that still default to unstructured aren’t ignoring this evidence; most haven’t seen it.
Why unstructured interviews matter
Unstructured interviews matter because most companies still run them. Understanding the unstructured baseline is what makes the case for structure.
They also amplify bias more than any other interview format — the absence of standardised questions makes it easy for affinity bias, halo effect, and similarity bias to dominate decisions invisibly. For VPs of TA trying to improve hiring quality, retiring unstructured interviewing is usually the largest single opportunity.
The change isn’t expensive; it’s cultural. Hiring managers who’ve always run unstructured interviews resist structure as bureaucratic until they see the difference in hire quality six to twelve months later.
Common mistakes and misconceptions about unstructured interviews
- Believing unstructured interviews surface “the real candidate.” They surface what the interviewer wanted to find. Different interviewers find different things in the same person.
- Mistaking rapport for predictive power — Unstructured interviews often feel better, but feeling better and predicting performance better are different things — and in this case, opposed.
- Assuming bias is the interviewer’s individual problem — Unstructured format is the bigger driver. Even bias-aware interviewers default toward affinity decisions when the format gives no scoring anchor.
- Thinking experienced interviewers don’t need structure — Senior interviewers actually show more variance in unstructured formats than junior ones, because their pattern-matching is stronger and more idiosyncratic.
- Calling an interview “structured” because there’s an interview guide — A guide isn’t structure. Predefined questions, scoring rubric, and independent scoring are the actual components.
Frequently asked questions
What is an unstructured interview?
An unstructured interview is a hiring conversation that follows no predefined question set or scoring rubric. The interviewer asks whatever feels relevant, and the assessment relies on overall impression rather than evidence against fixed criteria. Each interviewer follows their own line of questioning, candidates get asked different things, and the debrief turns on personal impressions rather than scored evidence.
Why are unstructured interviews still common if structured interviews are better?
Because unstructured feels easier and more natural to interviewers. Structure requires preparation, agreement on competencies, and rubric design. Most hiring managers haven't seen the performance evidence and resist structure as bureaucratic. The move to structured interviewing is usually a cultural change, not a technical one.
Is there ever a good reason to run an unstructured interview?
For informal relationship-building — coffee chats with passive candidates, networking conversations, founder-to-founder discussions for senior hires — unstructured conversation has a place. As the formal assessment that drives the hiring decision, the evidence consistently favours structured formats.
Do unstructured interviews increase hiring bias?
Yes. Without standardised questions and scoring, affinity bias, halo effect, and similarity bias have more room to drive decisions. Different candidates get asked different things, scored against different mental criteria, and judged by different impressions. Structure is the most reliable counter.
How do you tell if your company runs unstructured interviews?
Check three things: do all candidates for the same role get asked the same questions, do interviewers score against a written rubric, do interviewers submit scores before the debrief discussion. If any answer is no, the interview is partially or fully unstructured regardless of what it's called internally.