If we test the mean amount that alcoholic subjects drink before and after therapy, and that difference is NOT statistically significant, this could mean
A) the therapy was not effective.
B) the sample size was too large.
C) the study lacked sufficient power.
D) a and c

Question

Quizplus · Accepted Answer

The lack of statistical significance in the difference could mean that the therapy was not effective (A) or that the study lacked sufficient power to detect a difference if one exists (C). A large sample size typically increases the power of a study, making B an incorrect choice.

If We Test the Mean Amount That Alcoholic Subjects Drink