Summary & Key Takeaways ​

• Rigorous selection criteria are essential for protecting the validity of user studies.
• The article explains how to define clear inclusion criteria to specify who should be part of the study.
• It covers exclusion criteria to identify who should not participate.
• Guidance is provided on incorporating diversity criteria to ensure a representative participant pool.
• Proper participant selection helps avoid costly misrecruits and improves research outcomes.

Our Commentary ​

This is a classic NNGroup article: clear, practical, and absolutely essential for anyone involved in UX research. Participant selection is often overlooked or rushed, leading to skewed results and wasted effort. We've all been there, realizing too late that our participant pool wasn't quite right. This guide is a fantastic reminder of the fundamentals – defining inclusion, exclusion, and diversity criteria isn't just academic; it's critical for the integrity and actionable insights of any study. It's a foundational piece that every researcher should revisit periodically.