Section 04
How to hire well in Ontario — what actually predicts whether a hire works out, how to run a process you can defend, and how to onboard so good people stay.
Hiring well is mostly a measurement problem: most of the signals employers lean on — a good chat, a confident handshake, a gut feeling — barely predict who will actually do the job, and the few signals that do are the ones most small employers skip.
For two decades the research had a settled hierarchy of what predicts job performance, and in 2022 a major reanalysis corrected it. The short version: a structured interview — the same job-related questions, the same scoring, every candidate — is now the single strongest predictor, while the free-flowing “let’s just chat and see if I like them” interview that most hiring runs on is among the weakest tools in common use. And no single method predicts well enough on its own — adding one more job-relevant read beats relying on a conversation. None of this is exotic or expensive; it’s mostly a matter of doing on purpose what most employers do by feel.
It’s worth being just as careful about the scare numbers. The cost of a hire that doesn’t work out is real — but the figures that saturate HR blogs mostly aren’t. The famous “a bad hire costs 30% of first-year earnings, per the U.S. Department of Labor” line can’t be traced to any actual Department of Labor document, and the “strong onboarding lifts retention 82%” claim is an uncited vendor figure. We don’t use either. What follows is the evidence that survives scrutiny, the process it points to, and where each part links down to the sourced note behind it.
The evidence
Peer-reviewed selection research, corrected to the current (post-2022) figures — not the inflated numbers that still circulate online.
Verified
The strongest predictor
A structured interview — the same job-related questions, asked of every candidate and scored on a set scale — is the single strongest predictor of job performance, at the head of a tight top group with job-knowledge and work-sample tests. Most hiring never builds one.
Sackett et al. (2022) Journal of Applied Psychology — meta-analytic reanalysis
The selection-validity hierarchy ›Verified
The 2022 correction
Cognitive-ability testing was sold for years as the #1 predictor at around .51. A 2022 reanalysis corrected a statistical over-correction and revised it down to about .31 — no longer the stand-out signal. If you read “cognitive ability is the best predictor at .51,” you’re reading pre-2022 numbers.
Sackett et al. (2022) Journal of Applied Psychology
What the 2022 reanalysis changed ›Verified
The weakest common tool
The unstructured interview — the open-ended “let’s just chat” — is among the weakest and most bias-prone tools in common use (revised to about .19). Structuring the interview you already run roughly doubles its predictive value.
Sackett et al. (2022) Journal of Applied Psychology — meta-analytic reanalysis
Structured vs. unstructured interviews ›Validity coefficients are estimates with real spread, not fixed constants — read them as the best current evidence on the rank order of methods. General information, not legal advice.
Practice — not law
This is the method that turns the evidence into a repeatable process — six stages, selection through onboarding, and where each one tends to go wrong. None of it is a legal citation; it’s what good hiring looks like in practice. One finding shapes the whole sequence: no single method predicts well enough on its own, so the strongest and most defensible hires combine two job-relevant methods rather than resting on one conversation.
Before you write the ad, do a quick job analysis: the few things the role genuinely needs to succeed, separated from the long wish-list. That short list becomes your criteria, and everything downstream is measured against it.
What predicts performance ›Where it goes wrong “Culture fit” used as an unexamined euphemism. Undefined, it usually just means “people like us” — and it can quietly drift into screening by age, background, or another protected ground. Name the specific behaviours the job actually needs instead.
Write job-related questions and a simple scoring guide before you meet anyone — situational (“what would you do if…”) or behavioural (“tell me about a time…”) questions tied to the criteria, with what a good answer looks like decided in advance.
What makes an interview structured ›Where it goes wrong Making it up in the room. Questions invented on the fly can’t be compared across candidates, so the “data” is noise — and noise is exactly where first-impression and similarity bias fill the gap.
Ask the same questions in the same order, score each answer as it’s given, and — where you can — use more than one trained interviewer who rate independently, then compare. Consistency is what turns an interview into a measurement.
Conducting a structured interview ›Where it goes wrong The unstructured “let’s just chat” interview — the default for most small employers, and one of the weakest, most bias-prone tools there is. A warm conversation feels like insight, but mostly it measures rapport, not who can do the job.
Pair the interview with one more job-relevant method: a work sample or job-knowledge test for experienced hires, a cognitive measure where you’re hiring for learning potential. Use references late, to verify facts and catch red flags — not to rank finalists.
Why combining methods works ›Where it goes wrong The halo effect — one strong impression (a confident talker, a shared school, a great first five minutes) colouring every other judgment. And treating a glowing reference as prediction: candidates pick their own referees, and few referees say anything negative.
Bring the scores together, weight verified facts over impressions, make the call, and write down why. A documented, job-related decision is both a better decision and a defensible one if it’s ever questioned.
Using references and checks well ›Where it goes wrong Deciding on gut and back-filling the reasons afterward — or letting the most confident person in the room override what the process actually found.
The hire isn’t done at “yes.” Start before day one, give real role clarity and one early win in the first week, and run a manager-owned check-in rhythm through the first 90 days. You’re building three things on purpose: role clarity, the confidence to do the work, and a sense of belonging.
A good first 90 days ›Where it goes wrong Sink-or-swim onboarding — handing the new person a laptop and hoping. The manager, not HR or a checklist, is the part that moves whether they stay; in a small firm that’s an advantage, because the manager already sees them every day.
Most hiring runs on the least predictive signal there is — a conversation you can’t quite explain afterward. The fix isn’t a better gut. It’s a process.
Verified
The cheapest upgrade in hiring
Structuring the interview you already run roughly doubles its predictive power — no software, no consultant, just job-related questions and a scoring guide. It’s the highest-return, lowest-cost change most employers can make.
Sackett et al. (2022) Journal of Applied Psychology
Structured interviews ›
Article Hire with Confidence Executive search Hiring a role you can’t afford to get wrong? Book a consultation A real decision
For a routine role, your own structured process is plenty. When you’re hiring a senior leader or a hard-to-reach specialist, you face a real choice in how you engage outside help. The split isn’t really about fees — it’s about exclusivity, research depth, and reach into people who aren’t job-hunting.
When the role is senior or critical
When the pool is deep and speed matters
Fee conventions you’ll see quoted (a percentage of first-year pay, paid in instalments) are U.S. industry norms, not Canadian rules — treat them as illustrative. A Kitchener–Waterloo firm hiring its first VP is the classic retained case; routine professional hires usually aren’t. Executive search: retained vs. contingency ›
From the blog
Article So what’s it like to be a real-life headhunter? What separates a real headhunter from a contingency recruiter — a VP of Finance search, start to finish. Read › 
Article Team Dynamics – Hiring the Right People & Creating Effective Teams Hiring the right people, and building a team that actually works once they’re in. Read › 
Article Solving the Talent Challenge A year of roles filled across Ontario — IT directors to warehouse staff — and what the searches had in common. Read › Questions employers ask
On the best current evidence, a structured interview is the single strongest predictor, with job-knowledge and work-sample tests close behind. Cognitive-ability testing — long sold as the top predictor — was revised down in 2022 and now sits mid-pack. In practice, most hiring relies most on the weakest predictors, while the strongest are inexpensive to add.
The selection-validity hierarchy ›Yes — if they’re structured. A structured interview (same job-related questions, same scoring, every candidate) is the strongest single predictor there is; the unstructured “let’s just chat” version is among the weakest and most bias-prone. Structuring the one you already run roughly doubles its predictive value.
Structured vs. unstructured interviews ›Ontario’s Human Rights Code bars job ads, application forms, and interview questions from sorting people — directly or indirectly — by a protected ground. That catches indirect signals too: “young, energetic team” in an ad, or availability questions that really probe family status or religion. You may ask about a protected ground only in the narrow cases the Code itself allows (a genuine job requirement). General information, not legal advice — if a question feels close to the line, get advice before you ask it.
Job ads, applications & interview questions ›Yes. Under Ontario’s accessibility rules you must tell applicants accommodation is available in your recruitment process, offer it when you invite someone to a test or interview, and point a successful applicant to your accommodation policies when you make the offer. The duty resets at each stage — posting the line once isn’t enough — and it sits on top of your broader duty to accommodate under the Human Rights Code.
Accessible recruitment under AODA ›Build three things on purpose in the first months: role clarity, the confidence to do the work, and a sense of belonging. Structured onboarding — preboarding, a real first week, an early win, and a manager-owned check-in rhythm — is well-evidenced to support those, and they predict staying and performing. Be wary of the viral “82% retention” onboarding stat, though: it’s an uncited vendor figure. The honest claim is strong enough without it — the manager, not the checklist, is what determines whether a new hire stays.
Does structured onboarding reduce turnover? ›A hire that doesn’t work out costs more than the recruiting bill, but the widely quoted figures are unreliable. The famous “30% of first-year earnings, per the U.S. Department of Labor” line can’t be traced to any real DOL document — treat it as apocryphal. What is solid, on the research, is that the cost rises sharply with seniority: top performers in senior roles contribute out of all proportion, so a bad senior hire is disproportionately expensive. That’s the case for spending real care — and sometimes a retained search — on the hires you can’t afford to get wrong.
What a bad hire costs ›The knowledge base
Executive search & hiring
Whether it’s your first senior leader, a hard-to-fill specialist, or just a process that keeps producing hires that don’t work out, that’s worth a conversation before the offer goes out — not after. We run structured, evidence-based searches, and we’ll tell you honestly when a role doesn’t need one.