The participant said no.

The form was signed. The participant left. And somewhere in the walk back to the parking garage, the participant turned to a family member and said: "I am not really sure what I just agreed to, but the coordinator seemed to think it was straightforward."

This is not an unusual outcome. It is the usual outcome. And it represents, in my view, the single most dangerous false positive in our field -- the moment when a coordinator concludes that comprehension has been achieved because the participant said "no" to a question that was never designed to detect comprehension in the first place.

This lesson is about that gap. Not about how to close it -- we will get to that in the lessons that follow. But about understanding, with clarity and evidence, why it exists. Because if you do not appreciate the size and nature of this problem, you will not be motivated to adopt the solutions.

The participant said no.

The form was signed. The participant left. And somewhere in the walk back to the parking garage, the participant turned to a family member and said: "I am not really sure what I just agreed to, but the coordinator seemed to think it was straightforward."

This is not an unusual outcome. It is the usual outcome. And it represents, in my view, the single most dangerous false positive in our field -- the moment when a coordinator concludes that comprehension has been achieved because the participant said "no" to a question that was never designed to detect comprehension in the first place.

This lesson is about that gap. Not about how to close it -- we will get to that in the lessons that follow. But about understanding, with clarity and evidence, why it exists. Because if you do not appreciate the size and nature of this problem, you will not be motivated to adopt the solutions.