A new screening test has been developed for syndrome Q. Research has shown that the test yields a positive for syndro...

on October 25, 2019

Describe the flaw

Hello, will you explain why A is the right answer? Thank you!

1 Reply

Irina on October 25, 2019


The argument tells us that whenever the person has a syndrome, the test yields a positive.


It then concludes that because a person shows positive, she must have the syndrome.


This is a logical fallacy of affirming the consequent or mistaken negation, we cannot conclude that just because someone's test result is positive, they definitely have a syndrome, after all it might be a false positive.

(A) accurately describes this flaw, the claim is that S -> P, not that P -> S, therefore, it is the correct answer.

Let me know if you have any other questions.