4. Mistakes to avoid

Don't ask the testers to tell you how they used the product, as that's for you to observe. Instead, ask them why they acted a certain way at a certain moment in the experiment.

Avoid places where the product is staged in an artificial way (e.g. a car show). People trying out vehicles or other products will not behave naturally.

Don't go for quantity at all costs; instead, spend more time with a few testers, who will bring out any unexpressed needs.