Here’s where pre-employment testing makes all the difference. Properly validated assessments take the subjectivity out of hiring and give you hard evidence about a candidate’s suitability.

Some of the most effective tests in high-risk settings include:

• Cognitive ability tests: Can they problem-solve, process information quickly, and make sound decisions under pressure? Think air traffic controllers.

• Personality and behavioural assessments: Do they show traits like conscientiousness and resilience? Mining companies use these to identify candidates more likely to follow safety rules.

• Emotional intelligence testing: How well do they handle conflict, stress, or teamwork? Law enforcement agencies use tools like MSCEIT to predict how officers respond in the field.

• Safety assessments: Who’s likely to cut corners, take risks, or ignore procedures? These tests flag red-zone behaviours before they become a liability.

The point is simple: if you can prove your assessments are job-relevant and scientifically valid, your process becomes much harder to challenge.

So how do you build one? Here are the essentials:

1. Start with job analysis

Know exactly what the role demands. Skills, behaviours, and risks. Document it. For a drone operator, that might mean attention, decision-making, and stress management. For an aged-care nurse, it’s empathy, resilience, and teamwork.

2. Use validated tools

Only use assessments backed by research. According to the APA, cognitive ability testing predicts job performance with a correlation of 0.51 — one of the strongest predictors available.

3. Standardise the process

Every candidate should complete the same steps under the same conditions. Structure interviews, use scoring guides, and keep it consistent.

4. Keep your records straight

Document your job analyses, test results, interview notes, and decision criteria. If challenged, you’ll need that evidence.

5. Train your hiring managers

Even the best system falls down if managers default to gut feel. Training helps them understand results, reduce bias, and follow process.

Pitfalls to avoid

• Relying on gut feel: it’s indefensible, and it won’t protect you if challenged.

• Using cheap, unvalidated tools: if it’s not scientifically proven, it won’t stand up in court.

• Failing to update processes: laws and risks change. Review your processes regularly.

• Ignoring data: if one group of candidates is consistently excluded, you need to investigate adverse impact.

The ROI of defensibility

This isn’t just about legal protection. A defensible hiring process delivers real business benefits:

Lower mis-hire risk. Valid, job-relevant selection methods (e.g., cognitive ability tests + structured interviews) are among the strongest predictors of job performance — a century of research backs this, with modern updates refining effect sizes by criterion and method. 

Longer tenure. An NBER study comparing manager discretion to pre-employment testing found that relying on test recommendations produced hires who stayed longer than those chosen by managers going against the scores. In other words, following validated test signals improves retention. 

Concrete cost impact. Turnover is expensive: Gallup estimates replacing an employee typically costs 0.5× to 2× annual salary (and up to ~200% for leaders/managers). Reducing mis-hires and early exits meaningfully lowers that bill.