Rail Business Daily Guest Writer Feature: Selection That Stands Up
Why validation studies for assessment tools are essential in safety-critical recruitment
Written by Dr Stephen Fletcher, Joint CEO and Occupational Psychologist at the OPC. Published in Rail Business Daily’s News Bulletin – 10th and 19th June, 2025.
In this expert Guest Writer article, Dr Stephen Fletcher explains the vital role validation plays in safety-critical recruitment. Validation is a scientific process used to ensure that selection tools, e.g., psychometric tests or structured interviews can genuinely help to predict who is more likely to perform well and work safely.
In high-risk industries like rail, transport, or the engineering sector, where the consequences of human error can be severe, using validated recruitment tools isn’t just good practice — it’s essential. Validated selection methods give employers confidence that they’re choosing individuals who are less likely to make critical errors, helping to build a stronger safety culture and reduce operational risk.
Dr Fletcher offers a clear breakdown of the steps involved in a typical validation study, comparing candidates’ historical assessment scores with real-world performance data such as training outcomes, supervisor ratings, or safety metrics. Where a strong correlation exists, it provides compelling evidence that the tool is accurate in its measurement of what matters, helping to ensure fair, effective, and legally defensible recruitment decisions.
The article outlines the benefits of validation studies for both organisations and candidates. Dr Fletcher also notes some other strategic advantages, including refining recruitment processes, fine-tuning assessment tool weightings, and enabling continuous improvement.
Drawing on practical case studies from both the rail and aviation sectors, the article shares some valuable insights and lessons learned from his extensive experience of validation work.
"Validation, is a powerful tool for continuous improvement. It sharpens recruitment practices, helps measure what truly matters, and ensures selection decisions stand up to scrutiny."
Dr Stephen Fletcher, Joint CEO and Occupational Psychologist at the OPC
Read the full Guest Writer feature to discover how validation could strengthen your recruitment outcomes.
Get in touch with the friendly OPC team if you'd like to explore how our validation services can help you build safer, more effective teams.