Identify the most likely pitfall. "Your friend Bill believes he can heal anyone from illness by chanting their name whil

[answerhappygod]

Identify the most likely pitfall. "Your friend Bill believes he
can heal anyone from illness by chanting their name while holding a
special crystal. He agrees on a test of this claim. You find 20
people who are sick and split them randomly into two groups. He
chants the names of the people in one group while holding his
crystal, and you check to see how well the two groups feel
afterward. In the end, there is no difference between the two
groups. When confronted with these results, Bill argues that his
healing powers do not work unless everyone watching has full faith
in the process."
Neglect of total evidence
Neglect of priors
One-sided strength test
Ad hoc modification