If experimental treatments produce an effect:
A) between-groups variance will increase
B) between-groups variance will decrease
C) within-groups variance will increase
D) within-groups variance will stay the same

Question

Quizplus · Accepted Answer

When experimental treatments produce an effect, it means that the groups being compared are becoming more different from each other in terms of their means. This difference increases the between-groups variance, as there is a larger spread in the group means.

If Experimental Treatments Produce an Effect