An unstructured interview is a conversation in which an interviewer forms an impression in the first few minutes and spends the rest of the time confirming it. It feels informative. It is largely a measure of rapport.
For a related Monitask resource on self-reporting bias, see this page.
A structured interview asks every candidate the same questions, tied to defined competencies, scored against defined criteria. It is less enjoyable to conduct and considerably more predictive.
The change costs nothing but preparation.
What goes wrong without structure
Different candidates get different interviews. One gets asked about a hard project, another gets a chat about a shared university. You cannot compare them, because you did not measure the same thing.
First impressions dominate. Judgements form early, and later questions get read as evidence for the conclusion already reached.
Similarity gets mistaken for quality. Interviewers rate people like themselves higher. Without criteria to anchor against, "good fit" often means "reminded me of me."
Nothing is written down. Debriefs run on recollection, and the loudest opinion wins.
It creates legal exposure. Inconsistent questioning across candidates is difficult to defend if a hiring decision is later challenged.
Building one
1. Define the competencies
Four to six, no more. Each should be something the job genuinely requires and that can be evidenced.
Not "communication skills" — that is too broad to score. Something like "can explain a technical decision to a non-technical stakeholder and get agreement."
Derive them from the work, not from a template. The fastest route: ask what the last person in this role struggled with, and what the strongest performer does differently.
2. Write the questions
Two or three per competency, asked of everyone.
Behavioural — "Tell me about a time you had to change a plan after work had started. What happened?" Past behaviour, described specifically.
Situational — "You are two weeks from a deadline and a dependency slips. Walk me through what you do." Useful where the candidate has not held the exact role.
Work sample — the strongest signal available, where the job allows it. A short, realistic, paid or time-boxed task beats any question.
Write the follow-up probes in advance too: what specifically did you do, what was the outcome, what would you do differently. Candidates default to describing what the team did; the probes get you to what they did.
3. Build the scorecard
For each competency, define what a weak, adequate, and strong answer looks like — in writing, before the interview.
A 1–4 scale works better than 1–5, because it removes the safe middle. Force a lean.
Interviewers record a score and a short evidence note for each competency, immediately after the interview and before speaking to anyone else.
4. Split the competencies across interviewers
If three people interview, each covers two competencies in depth rather than all six shallowly. This removes the repetition candidates find exhausting and produces deeper evidence.
5. Run the debrief properly
Everyone submits scores before the discussion. Then compare.
The value is in the disagreements — where one interviewer scored a 2 and another a 4, someone saw evidence the other missed. That conversation is the point. If scores are collected after discussion, the first person to speak sets the answer.
What to ask about instead of the usual
Replace "what is your greatest weakness" — everyone has a rehearsed answer. Ask: "What part of your current role do you find hardest, and how do you handle it?"
Replace "where do you see yourself in five years" — measures imagination. Ask: "What would make you consider this a good move a year from now?"
Replace "tell me about yourself" as an evaluation question. It is fine as an opener; do not score it.
Replace hypothetical brain teasers. They predict little except comfort with brain teasers.
Legal ground
Consistency is your best protection as well as your best signal.
Do not ask about protected characteristics or their proxies — age, family plans, national origin, religion, disability, and in many jurisdictions salary history, which is prohibited in a growing number of states and cities.
Ask everyone the same questions. Keep the scorecards. If a decision is ever challenged, contemporaneous written criteria applied consistently is the strongest thing you can produce.
See interview questions that create EEOC exposure.
Keep the process short
Structure lets you cut stages, because each one produces real evidence rather than an impression.
Three well-designed stages usually beat five loose ones — and every additional stage costs internal hours and gives candidates time to accept other offers. See what it really costs to fill a role.
Where to start
If you change one thing this quarter: write down four competencies and a scorecard, and have interviewers submit scores before the debrief.
That single change removes most of the anchoring problem and gives you something to compare. Everything else on this page is refinement.
PJP builds interview frameworks and trains the managers who run them. HR consulting → For broader reference, consult EEOC employer guidance.