Hiring Strategy: Structured Interviews • Candidate Comparison • Candidate Evaluation
Most hiring managers have conducted interviews that felt productive.
The conversation flowed naturally. The candidate was engaging. Everyone in the room came away with a strong impression.
Then the person was hired.
Six months later, the team was wondering how they got the decision so wrong.
One reason is that a good conversation and a good hiring assessment are not necessarily the same thing.
An unstructured interview can feel informative because the interviewer is free to follow interesting topics, probe whatever catches their attention, and build rapport with the candidate.
A structured interview deliberately gives up some of that freedom.
Candidates are evaluated against the same job-related criteria. They are asked the same core questions. Their answers are scored using the same standards.
That can feel less natural.
But if the purpose of the interview is to predict how someone will perform after being hired, the research generally favors the structured approach.
A major 2022 review of personnel-selection research estimated the relationship between structured-interview performance and subsequent job performance at about r = .42, compared with about r = .19 for unstructured interviews. In that analysis, structured interviews had the highest average validity among the selection procedures examined.
Those numbers are correlations, not percentages of successful hires, and researchers also found considerable variation among individual interview systems.
That distinction matters.
The lesson is not that adding a list of questions magically turns an interview into a reliable predictor.
The lesson is that how you design, conduct, and score the interview matters.
What Is Predictive Validity?
In hiring, predictive validity describes how strongly performance on a selection method is related to later job performance.
If candidates who score well during an interview also tend to perform well after being hired, the interview has useful predictive validity.
If interview scores have little relationship with subsequent performance, the interview may feel informative without actually helping the organization distinguish stronger candidates from weaker ones.
That is one of the difficulties with interviewing.
Humans are very comfortable having conversations.
We are also very comfortable forming impressions of other people.
Those abilities can make us feel confident about our hiring judgments even when the process we used to reach them was inconsistent.
A structured interview attempts to turn the interview from an impression-forming conversation into a more consistent form of evidence gathering.
What Is an Unstructured Interview?
An unstructured interview is the familiar conversational interview.
The interviewer may begin with something like:
Tell me about yourself.
From there, the conversation develops naturally.
One candidate mentions managing a difficult project, so the interviewer spends ten minutes talking about project management.
Another candidate mentions a shared industry connection, leading to a conversation about people they both know.
A third candidate is unusually personable, so the interview becomes an engaging discussion about leadership philosophy.
None of those conversations is necessarily useless.
The problem comes when the hiring team later tries to compare the candidates.
They were effectively given different tests.
One candidate was evaluated heavily on technical experience.
Another had more opportunity to demonstrate communication ability.
Another spent considerable time discussing leadership.
The hiring team may still select someone.
But it becomes difficult to determine how much of the decision is based on comparable evidence and how much comes from overall impression.
What Makes an Interview Structured?
A structured interview does not have to sound robotic.
Structure means that the organization determines in advance what it is trying to evaluate and creates a consistent process for gathering that evidence.
The U.S. Office of Personnel Management describes structured interviews as using standardized questions and scoring procedures tied to job-related competencies. Candidates receive the same predetermined questions, and responses are evaluated against common rating standards.
OPM also notes that greater interview structure is associated with higher validity, reliability, and agreement among interviewers.
The important elements usually include:
- Defining the competencies required by the job
- Asking candidates the same core questions
- Using questions tied to those competencies
- Establishing scoring criteria before conducting the interview
- Having interviewers rate evidence consistently
- Comparing candidates against the requirements of the role
The conversation can still include reasonable follow-up questions.
The difference is that the interviewer is not deciding in real time what each candidate should be evaluated on.
For additional guidance, see the U.S. Office of Personnel Management’s overview of structured interviews.
Why Unstructured Interviews Feel So Good
If structured interviews have better research support, why are conversational interviews still so common?
Part of the answer is simple.
They feel natural.
A skilled manager may have spent decades developing an ability to talk with people and form judgments quickly.
An experienced interviewer may believe:
I can usually tell within fifteen minutes whether someone will work out.
Sometimes that judgment will be right.
But there is a problem hidden inside that statement.
It is difficult to remember all of the candidates who felt right and later failed.
It is equally difficult to know how many excellent candidates were rejected because they did not create the right impression during the conversation.
The interviewer receives strong feedback from the people who were hired.
There is much less feedback about the people who were rejected.
That makes intuition difficult to calibrate.
The Interview Can Start Measuring the Interview
Suppose you are hiring a maintenance manager.
The person who will ultimately succeed may need to:
- Diagnose equipment problems
- Prioritize work
- Enforce safety requirements
- Coach technicians
- Coordinate with production
- Manage vendors
- Make good decisions during breakdowns
Now imagine two finalists.
Candidate A is highly polished in interviews. They answer quickly, maintain eye contact, tell compelling stories, and establish rapport immediately.
Candidate B is more reserved. Their answers are slower and less polished, but they have substantial technical experience and strong examples of solving exactly the kinds of problems the job requires.
In an unstructured interview, Candidate A may simply feel stronger.
But what did the interview actually measure?
Perhaps communication skill.
Perhaps confidence.
Perhaps social fluency.
Perhaps similarity with the interviewer.
Perhaps preparation for interviews.
Those qualities may matter to the job.
But they may not deserve the amount of influence they receive merely because they are especially visible during an interview.
Structure helps bring the evaluation back to the work.
Structured Interviews Make the Job the Reference Point
This is probably the most important advantage.
A structured interview begins by asking:
What does successful performance in this job actually require?
If one of the critical competencies is decision-making under pressure, the hiring team develops a question that gives every candidate an opportunity to demonstrate that competency.
For example:
Tell me about a time you had to make an important decision before you had all the information you wanted. What was happening, what did you decide, and what happened afterward?
Now every finalist addresses the same underlying requirement.
The interview team can compare the evidence.
Candidate A may describe acting immediately and successfully resolving a production emergency.
Candidate B may describe briefly gathering the most critical information before deciding.
Candidate C may reveal that they delayed until someone else made the decision.
Those are useful differences.
The hiring team is learning something about how the candidates have handled a job-related problem rather than simply deciding who interviewed well.
Structure Improves Comparability
Imagine interviewing three candidates with two interviewers.
With an unstructured process, you effectively have six separate conversations.
Each interviewer may remember different things.
One interviewer may especially value technical depth.
Another may respond strongly to confidence.
One candidate may have been asked difficult questions about mistakes.
Another may never have been asked about mistakes at all.
Then everyone meets afterward and tries to answer:
Who was strongest?
This is where comments such as these begin appearing:
I just liked Sarah better.
Mike seemed more senior.
Something bothered me about Jennifer.
Carlos really impressed me.
Those reactions may contain useful information.
But they are difficult to evaluate.
A structured process gives the hiring team something more concrete to discuss.
Instead of:
Who did you like?
the conversation becomes:
How did each candidate demonstrate the competencies we agreed were important?
That is a fundamentally different decision process.
Structure Also Improves Interviewer Agreement
One of the problems with interviewing is that two people can hear the same candidate and reach very different conclusions.
Some disagreement is inevitable.
But a good interview process should reduce unnecessary disagreement.
Higher levels of interview structure have been associated with greater rater reliability and agreement because interviewers have less discretion over what questions are asked and how responses are evaluated.
That does not require interviewers to reach identical conclusions.
In fact, independent judgment can be valuable.
A useful approach is for each interviewer to score the candidate’s responses independently before the interviewers discuss their ratings.
If one interviewer scores an answer highly and another scores it poorly, the disagreement becomes useful information.
They can ask:
What evidence did you hear that led you to that score?
That is much more productive than discovering after six interviews that everyone was using a different definition of “good candidate.”
The Questions Matter
Simply asking every candidate the same questions is an improvement in consistency, but it is not enough.
A structured interview with poor questions can still be a poor interview.
The questions should connect directly to the work.
OPM recommends developing structured interview questions from competencies identified through job analysis and using questions that are job-related, clear, open-ended, and designed to elicit evidence about how candidates have handled relevant situations.
Compare these two questions:
What is your biggest strength?
and:
Tell me about the most difficult equipment failure you were responsible for resolving. What was the situation, what did you personally do, and what was the result?
The first question may produce an interesting conversation.
The second gives the interviewer evidence connected to actual work.
For more on question design, see the OPM guidance on creating structured interview questions.
Behavioral Questions and Situational Questions
Structured interviews commonly use two broad kinds of questions.
A behavioral question asks what the candidate has done before.
For example:
Tell me about a time you had to address poor performance from an employee you personally liked.
A situational question presents a realistic scenario and asks what the candidate would do.
For example:
You discover that an experienced employee has repeatedly ignored a safety procedure because they believe it slows production. How would you handle the situation?
Both can be useful.
Behavioral questions provide evidence from actual past experience.
Situational questions can be especially helpful when candidates have not yet encountered the exact situation being evaluated.
OPM describes both formats as established approaches for assessing job-related competencies through structured interviewing.
The Scoring System Matters Too
Consider this response to a leadership question:
One of my technicians was struggling, so I sat down with him, figured out where he was getting confused, changed the way we were training him, and checked back with him over the next several weeks. He eventually became one of our stronger technicians.
One interviewer might call that an excellent answer.
Another might call it average.
Without shared scoring criteria, both judgments are difficult to compare.
A structured interview should define what strong evidence looks like.
For a coaching competency, a strong response might demonstrate that the candidate:
- Identified the performance problem accurately
- Discussed it directly with the employee
- Provided useful support
- Established expectations
- Followed up
- Achieved a meaningful result
Now the rating is tied to evidence.
The interviewer still exercises judgment.
But the judgment has boundaries.
Structured Does Not Mean No Follow-Up Questions
One concern managers sometimes have is that structured interviews will prevent them from digging deeper.
That is not necessary.
Follow-up questions can be extremely useful.
If a candidate gives a vague answer, the interviewer may ask:
What was your personal role?
What did you actually say?
What happened next?
How did you know the problem was resolved?
The important thing is that follow-up questions clarify the evidence rather than turning the interview into a completely different experience for each candidate.
The core evaluation remains consistent.
What Does the Research Actually Say?
For decades, research has generally found that greater interview structure improves the usefulness of employment interviews.
More recent research has also caused researchers to revise some older estimates downward.
Sackett, Zhang, Berry, and Lievens revisited widely cited validity estimates in a 2022 Journal of Applied Psychology meta-analysis. They argued that previous research had often overcorrected statistically for restriction of range, which inflated estimates for many selection methods.
After revising those corrections, structured interviews still emerged with the highest mean validity among the selection procedures they examined, at approximately .42, while the estimate for unstructured interviews was approximately .19.
You can review the study through PubMed.
That does not mean a structured interview is “42% accurate” or that an unstructured interview is “19% accurate.”
Those numbers are correlation coefficients describing the relationship between interview results and later job performance.
It is also important not to interpret the difference as a guarantee that every structured interview will outperform every unstructured interview.
Researchers have noted considerable variation among structured interview systems.
The quality of the process still matters.
More Structure Is Generally Better Than Less Structure
Interviewing is not simply divided into two categories where an interview is either perfectly structured or completely unstructured.
There is a continuum.
A company might ask every candidate the same questions but have no defined scoring system.
Another might use standardized questions and scoring criteria but allow interviewers substantial flexibility in follow-ups.
A highly structured process might define the competencies, standardize core questions, provide specific follow-up guidance, use anchored rating scales, and require independent interviewer scoring.
Research summarized by OPM indicates that interviews with higher levels of structure generally demonstrate higher validity, rater reliability, and rater agreement.
That means an organization does not have to redesign its hiring process overnight to gain value.
Adding thoughtful structure can improve an existing process.
Structure Helps Reduce the Influence of First Impressions
Suppose the first candidate walks into the interview and immediately connects with the hiring manager.
They attended the same university.
They have similar professional backgrounds.
They laugh at the same things.
The conversation is easy.
The next candidate does not create the same connection.
An unstructured process gives those feelings a great deal of room to influence the decision.
A structured process does not eliminate human bias.
Nothing does.
But it forces the interviewer to return to the evidence.
What did Candidate A actually demonstrate about managing conflict?
What did Candidate B demonstrate?
How did each candidate perform against the same standard?
The structure acts as a constraint on the temptation to convert rapport into evidence of job performance.
Structure Helps With the Candidate Who Interviews Beautifully
Some people are exceptionally good at job interviews.
That is a skill.
Whether it predicts success depends on the job.
An excellent interviewer may have practiced common questions dozens of times.
They may understand what interviewers want to hear.
They may have compelling stories ready.
That does not make their answers dishonest.
But it means polish itself should not become the evaluation.
Structured questions with specific follow-up probes make it harder to rely entirely on general statements.
If someone says:
I believe strongly in holding myself accountable.
the interviewer can ask:
Tell me about a specific decision you made that failed. What part of the outcome was your responsibility?
Now the candidate has to provide evidence.
Structure Helps With the Candidate Who Does Not Interview Beautifully
The opposite problem matters too.
A strong candidate may be nervous.
They may need more time to formulate an answer.
They may be less socially polished.
They may communicate differently from the interviewer.
A loosely structured conversation can penalize those differences because the interviewer is evaluating the overall interaction.
A structured process gives the candidate repeated opportunities to demonstrate the competencies that actually matter.
They do not need to win the conversation.
They need to provide evidence that they can perform the work.
Structured Interviews Are Especially Useful With Multiple Interviewers
The value of structure becomes even clearer when several people participate in the hiring decision.
Suppose an HR director and department manager interview three finalists.
Without structure, each interviewer may pursue completely different lines of questioning.
Afterward, there may be plenty of information but very little comparable information.
With structure, both interviewers evaluate the same competencies and hear the same core questions.
They can score each answer independently.
Then they can compare their assessments.
Perhaps the HR director notices a strong example of employee coaching that the department manager undervalued.
Perhaps the department manager recognizes that an apparently impressive technical answer was actually superficial.
Now their different expertise improves the evaluation instead of creating two unrelated interviews.
Personality Assessments Fit Better Into a Structured Process
This is also where personality information becomes more useful.
A personality assessment may suggest that a candidate tends to be highly direct.
That should not become:
This person will be difficult to manage.
Instead, it might prompt the hiring team to pay particular attention to the candidate’s evidence around collaboration and disagreement.
A highly Steady candidate should not automatically be assumed to avoid conflict.
The interview can investigate how they have actually handled conflict.
An Investigative candidate may enjoy analytical problem-solving.
The interview can determine whether they have demonstrated the level of analysis the job requires.
As we discussed in What Personality Assessments Can—and Can’t—Tell You About a Job Candidate, personality information is strongest when it helps you decide what to explore rather than making the decision itself.
Structured interviews provide a way to do that exploration consistently.
What an Unstructured Interview Can Still Do Well
There is no need to eliminate normal human conversation from hiring.
Unstructured conversation can help candidates understand the organization.
It can help managers explain the role.
Candidates can ask questions.
Both parties can discuss expectations.
A hiring manager may want a final conversation with a finalist before making an offer.
The problem comes when an informal conversation is treated as though it provides the same kind of comparable evidence as a structured assessment.
The distinction is useful:
Use structured evaluation when you are measuring candidates.
Use normal conversation when you are communicating, recruiting, answering questions, and building the relationship.
The same meeting can even contain both, as long as the hiring team understands which part is being used to score the candidate.
A Practical Example
Imagine three finalists for a production supervisor role.
The hiring team has identified five important competencies:
- Decision-making
- Accountability
- Coaching
- Conflict management
- Operational discipline
Each candidate answers the same questions addressing those competencies.
Two interviewers score the answers independently.
Candidate A gives strong examples of fast decision-making and accountability but weaker evidence around coaching.
Candidate B demonstrates exceptional coaching and conflict-management experience but gives less convincing examples of making difficult decisions quickly.
Candidate C interviews very smoothly and creates an excellent initial impression, but several answers lack specific examples and receive lower scores when evaluated against the established criteria.
Now the hiring discussion becomes useful.
The team can see what each candidate demonstrated.
They can consider those findings alongside experience, technical qualifications, personality information, references, and other relevant evidence.
The interview has become an input into the decision rather than a contest to determine who creates the best impression.
For more on evaluating finalists using multiple sources of evidence, see How to Compare Job Candidates.
Structured Interviews Do Not Eliminate Judgment
Sometimes “structured” is interpreted as replacing human judgment with a formula.
That is not the goal.
Hiring requires judgment.
The challenge is giving people better evidence on which to base that judgment.
A rating scale cannot decide whether a particular coaching example is impressive.
An interviewer still has to understand the answer.
A scorecard cannot determine how much a particular strength matters relative to another candidate’s strength.
The hiring team still has to make that decision.
Structure improves the inputs.
It makes the reasoning easier to see.
Structure Also Makes the Final Decision Easier to Explain
Consider these two explanations for choosing a finalist.
The first:
Everyone liked him. He seemed confident and really knew his stuff.
The second:
He demonstrated the strongest evidence in the competencies we identified as most important for the role. Both interviewers independently rated him highly in operational judgment, accountability, and coaching, and those findings were consistent with his prior experience and references.
The second explanation does not guarantee that the hire will succeed.
Hiring always involves uncertainty.
But it is a much clearer explanation of why the decision was made.
That matters when the organization is trying to improve its hiring process over time.
Structured Interviews Are Not a Perfect Predictor
This point deserves emphasis.
A structured interview is still an interview.
Candidates know they are being evaluated.
They prepare.
They present themselves carefully.
Interviewers can misunderstand answers.
Scoring criteria can be poorly designed.
The wrong competencies can be selected.
Candidates can behave differently after they are hired.
Research showing meaningful predictive validity does not mean structured interviews eliminate bad hires.
Even though structured interviews performed strongly on average in updated research, results varied substantially among individual interview systems.
The practical takeaway is not:
Structured interviews solve hiring.
It is:
A well-designed structured interview gives you better evidence than relying primarily on an improvised conversation.
Better Hiring Comes From Multiple Sources of Evidence
An interview should not have to carry the entire hiring decision.
A strong process may also consider:
- Experience
- Technical qualifications
- Work samples
- References
- Personality assessment information
- Other evidence relevant to the job
Different methods answer different questions.
A resume tells you where someone has worked and what they claim to have accomplished.
A technical exercise may show whether they can perform an important task.
A personality assessment provides context about work style and preferences.
A structured interview helps you examine competencies, judgment, and past behavior consistently.
Candidate comparison helps bring those inputs together.
This is one reason the hiring process becomes stronger when each tool has a clearly defined job.
From Conversation to Evidence
Most organizations already interview candidates.
That means improving the interview does not necessarily require adding another step to hiring.
It means making better use of a step that is already there.
Define what the role requires.
Ask questions designed to reveal evidence about those requirements.
Give every finalist a comparable opportunity to respond.
Score the answers against common standards.
Have interviewers record what they heard before group discussion changes their impressions.
Then compare the evidence.
The interview can still feel human.
It simply becomes more deliberate.
Final Thoughts
Unstructured interviews are appealing because conversation feels informative.
Sometimes it is.
But hiring requires something more difficult than having an informative conversation.
You need to compare several people and make a prediction about how each will perform in a job they have not yet started.
Research generally gives structured interviews an advantage for that purpose, and a major modern review of selection research found structured interviews among the strongest available predictors of job performance.
The advantage comes from a straightforward idea:
Ask candidates about the things that actually matter for the job, give them comparable opportunities to provide evidence, and judge that evidence using the same standards.
You will still have to make a judgment.
But you will be making it with better information.
Explore more hiring resources in our articles on structured interviews, candidate comparison, and what personality assessments can and cannot tell you about candidates.
Frequently Asked Questions
Are structured interviews better than unstructured interviews?
Research generally finds that structured interviews provide stronger prediction of job performance and greater consistency between interviewers than unstructured interviews. The quality of the interview design still matters, so simply asking every candidate the same questions is not enough.
How well do structured interviews predict job performance?
A major 2022 meta-analysis estimated average criterion-related validity of approximately .42 for structured interviews. This is a correlation coefficient, not a percentage of correct hiring decisions, and results vary considerably among interview systems.
How well do unstructured interviews predict job performance?
The same modern review estimated average validity at approximately .19 for unstructured interviews. The research therefore supports greater interview structure, although actual effectiveness depends on how the interview is designed and used.
What makes a job interview structured?
Structured interviews typically use job-related competencies, predetermined core questions, consistent administration across candidates, and common scoring standards. More highly structured systems may also define appropriate follow-up probes and use multiple trained interviewers.
Does every candidate need to be asked exactly the same questions?
Candidates being evaluated for the same role should generally receive the same core job-related questions so their responses can be compared consistently. Clarifying follow-up questions can still be used when needed.
Can you ask follow-up questions in a structured interview?
Yes. Structure does not require interviewers to ignore incomplete answers. Follow-up questions can clarify what happened, what the candidate personally did, and what result followed while preserving the same underlying evaluation criteria.
Should interviewers score candidates separately?
Independent scoring can help preserve each interviewer’s judgment before group discussion influences it. Interviewers can then compare their scores and discuss meaningful differences using the evidence they heard from the candidate.
Do structured interviews eliminate hiring bias?
No hiring method eliminates bias. Structure can reduce opportunities for inconsistent evaluation by giving candidates comparable questions and rating standards, but interview design, interviewer training, and job-related criteria still matter.
Can personality assessments be used with structured interviews?
Yes. Personality information can provide context and identify areas worth exploring, while structured interviews allow hiring teams to investigate job-related behavior and competencies consistently. Personality results should complement rather than replace evidence about qualifications and past behavior.
Are structured interviews enough to make a hiring decision?
Usually, they are most useful as one source of evidence. Hiring teams may also consider qualifications, relevant experience, technical skills, work samples, references, personality insights, and other job-related information.
Hire Better and
Manage Smarter
We combine 3 proven, established assessments into one, giving you the most comprehensive view of a person.
Are you seeking an assessment for personal use? Click Here