If surgical procedure A has a higher success rate than surgical procedure B in every hospital where they are used and yet procedure B has a higher overall success rate, then we suspect that
A) Statement I: this is nonsense and it can't possibly be true.
B) Statement II: this is an example of Simpson's paradox.
C) Statement III: it must be easier to achieve success at some hospitals than at others, whatever procedure is used.
D) Statement IV: procedure B must be used predominantly in hospitals where it is easier to achieve success, while procedure A must be used predominantly where it is harder to achieve success.
E) Statments II, III, and IV are true.

Question

Quizplus · Accepted Answer

This scenario is a classic example of Simpson's Paradox, where a trend appears in several different groups of data but disappears or reverses when these groups are combined. This paradox can occur when there are underlying variables affecting the outcome, such as the difficulty level of cases or the expertise of hospitals. Thus, statements II, III, and IV all provide plausible explanations for the observed phenomenon.

If Surgical Procedure a Has a Higher Success Rate Than