Which is the most serious source of error in a study that compares a treatment group to a no-treatment group?
A) mortality
B) regression
C) selection
D) testing

Question

Quizplus · Accepted Answer

Selection bias is the most serious source of error in such studies, as it can lead to systematic differences between the groups that affect the outcome, making it difficult to attribute differences to the treatment itself.

Which Is the Most Serious Source of Error in a Study