Not a test

Ask parents not to step in to help their child, whether they notice their child is doing something incorrectly or even if their child asks for their help or input. Make clear that it’s okay if their kid doesn’t know how to do something. And if that’s the case, it’s the design’s fault, not their child’s.

Why this technique
Parents want to help their kids succeed. However, having parents step in will interrupt understanding how a kid uses the product alone.