The Anatomy of a Structured Interview

Part 1

Why most interviews predict so little

The largest meta-analysis of selection methods to date puts the validity of an unstructured interview at .19 and a structured one at .42.¹ In plain terms: the conversation most companies run before a hire is about as predictive as a coin flip with a slight lean. Adding structure more than doubles it, and puts the interview at the top of every method the study examined, ahead of work samples, cognitive tests, and personality inventories.

The reason is not mysterious. In an unstructured interview, every interviewer decides for themselves what to ask, what a good answer sounds like, and how much weight to give it. Two interviewers can meet the same candidate and leave with opposite conclusions, both sincerely held. The hiring manager then has to reconcile impressions, not evidence, and the strongest personality in the debrief usually wins.

Structure, as the research defines it, is two things.² First, how the questions are built: the same questions for every candidate, derived from the job, at a difficulty that matches the level. Second, how the answers are scored: fixed criteria, a fixed scale, and each interviewer rating independently before anyone talks. Most teams that say they run structured interviews have the first half. Very few have the second, and the second is where the validity comes from.

The practical problem is that building both halves for one role is a day of skilled work, and it has to be redone for every role. So it does not get done. This paper shows what the finished product looks like when it is.

Part 3

The example: a senior accountant at a manufacturing company

What follows is the plan Ratio generated for Inrock's senior accountant search, from the job description and the finance director's intake notes. It is shown as produced. The finance team used it to run the search; the role was filled in two weeks.

The skills model

Eight skills. The three must-haves are domain knowledge, which is right for a senior finance role: the hire has to run a close, own controls, and explain a variance on day one. The two core competencies are not must-haves, so they count toward the score but cannot cap it, yet they are the ones the finance director said separated the last good hire from the last bad one.

Left out on purpose

The posting also asked for the items below. Ratio kept them out of the interview and gave a reason for each.

Part 4

Two rounds, one skill at a time

Three skills in full: the two core competencies, because those are the skills most teams find hardest to interview for, and the top must-have. The remaining five are in the appendix. For each, the screening question, the hiring-manager question, and the anchors and follow-ups the interviewer sees under each.

Notice how the second-round question differs from the first. It is not a harder version of the same question. It is a specific scene from this job, with a constraint (two hours to close, a plant manager who will not move) that a prepared answer cannot route around. And notice the Relevance anchor in the second round: it names what an empty answer sounds like, so the interviewer knows the floor before the candidate starts talking.

Part 5

Scoring one answer

A plan is only as good as the rating it produces. Here is one answer to the Cross-Functional Alignment hiring-manager question, rated the way an interviewer would rate it in the room. The candidate answer is illustrative; everything the interviewer works from is the generated plan above.

Two things to take from it. The follow-up did real work: without the Trade-offs prompt, this answer would have read as a clean success story, and the interviewer would have had no idea the candidate's own review slipped. And the rating is defensible in a sentence: three of four, Relevance and Approach solid, Evidence specific, Trade-offs present but only when prompted. A second interviewer can disagree with that, but they have to disagree about the evidence, not the impression.

Part 6

What this changes for your team

For the recruiter

The screening round becomes a fixed thirty minutes with eight questions and a rubric, not a conversation that drifts. Ratings from the screen carry into the hiring-manager round, so the second interviewer starts from evidence instead of a summary email. The excluded-signals list is the answer to “why didn't you ask about the CPA.”

For the hiring manager

The hard questions are written, calibrated to the level, and come with the follow-ups. The manager spends the interview listening rather than inventing, and the debrief is a comparison of ratings on named skills. When a candidate is passed over, the reason is a skill and a rating, which is what a defensible decision looks like.

For HR

Every candidate for the role was asked the same questions and rated on the same criteria by people who scored independently. That is the standard the research, and an adverse-impact review, both look for. It is also a record: the plan, the ratings, and the evidence notes exist for every hire, not just the ones that go well.

References

1. 1.Sackett, P. R., Zhang, C., Berry, C. M., & Lievens, F. (2022). Revisiting meta-analytic estimates of validity in personnel selection. Journal of Applied Psychology, 107(11), 2040–2068. https://doi.org/10.1037/apl0000994
2. 2.Campion, M. A., Palmer, D. K., & Campion, J. E. (1997). A review of structure in the selection interview. Personnel Psychology, 50, 655–702.

Appendix

The remaining 5 skills

The rest of the plan, in the same form: Internal Controls, Financial Reporting, Cost Accounting, MS Dynamics NAV, MS Excel. The three must-haves are marked; Month-End Close, Internal Controls, Financial Reporting.