The Science behind Traitwise

Hiring Is Prediction — And Science Helps Lead the Way

At its core, hiring is prediction. Every hiring decision stands or falls with how well we can anticipate a candidate’s future success. However, even with the best intentions, assessing future performance remains a challenge. Hiring teams review CVs, conduct interviews, and check references—piecing together fragments of a candidate’s story in the hope of seeing the bigger picture.

It’s a situation not unlike weather forecasting: meteorologists also start with incomplete information about what lies ahead and must turn it into a reliable forecast. What makes their forecasts so much more accurate today is not guesswork, but the systematic use of data—satellite images, radar readings, historical patterns—all interpreted through the lens of scientific research. Hiring can benefit in precisely the same way.

Bringing Clarity to Hiring: Understanding Criterion-related Validity

Just as meteorologists rely on scientific tools to predict the weather, hiring teams can tap into scientific research to strengthen their hiring decisions. Over decades, researchers in Industrial and Organizational Psychology have investigated which selection methods best predict future job success.

A key outcome of this work is the concept of criterion-related validity—the extent to which the results of a selection tool correlate with later job performance. This relationship is measured by a validity coefficient (r), a value between 0 and 1, where higher numbers indicate stronger predictive accuracy.

What the Latest Science Reveals: Ranking Hiring Methods by Predictive Power

In 1998, Schmidt & Hunter published a large meta-analysis on the effectiveness of hiring methods. For years, it was considered the gold standard for understanding which tools best predict candidates’ job success.

Then in 2022, Sackett, Zhang, Berry & Lievens took a second look. Using more advanced statistical techniques, they corrected key flaws in the original analysis and released updated validity scores—refined estimates of each method’s predictive power (criterion-related validity) and its link to future job performance.

The result? A clearer, more realistic benchmark for hiring teams seeking to understand what truly works—and what doesn’t.

From Good to Great Prediction: Combining the Right Methods to Maximize Prediction Power

In recruitment, the goal is clear: to predict which candidates will thrive in a role. But no single assessment tool can provide a complete picture of a person’s potential. People are complex, and predicting future success requires looking at them from multiple angles.

For example, a test measuring cognitive abilities (GMA) can reveal how well someone might solve complex, unknown problems, but it doesn't offer insight into how they might interact within a team or handle feedback. Similarly, while a personality test (Big Five) can shed light on interpersonal skills, it won't predict how a person will perform under pressure or their specific motivation to succeed in the role.

This is where combining complementary methods becomes crucial, as it leads to a stronger, more reliable prediction of future job success—and ultimately enhances criterion validity, ensuring that the assessment accurately reflects the candidate’s potential to succeed in the role.

Turning Research into Results: The Traitwise Approach to Better Hiring

The science is clear: combining multiple, well-chosen selection methods leads to better hiring decisions. But in practice, applying this insight can be hard. Which methods are worth using? How do you ensure they work together? And how do you balance scientific depth with a good candidate experience?

The Traitwise Assessment is designed to solve exactly that.

The Traitwise Assessment combines three of the most predictive and complementary methods into one integrated tool: problem solving (GMA), workplace behavior (Big Five), and motivation drivers (Interests). Together, they answer the three questions that matter most in hiring:

• Can the candidate do the job? (problem solving)
• How will they do the job? (workplace behavior)
• Do they want to do the job? (motivation drivers)