If a repeated-measures study shows a significant difference between two treatments with α = .01,then what can you conclude about measures of effect size?
A)The value of Cohen's d is large.
B)The percentage of variance explained (r²) is large.
C)Both Cohen's d and r² are large.
D)A significant effect does not necessarily mean that the effect size will be large.

Question

Quizplus · Accepted Answer

A significant effect only indicates that there is a difference between the two treatments, but it does not provide any information about the magnitude of the difference or the effect size. Therefore, we cannot conclude anything about measures of effect size based solely on the fact that there is a significant difference between the treatments. Option A and B suggest that the effect size is large, which is not necessarily true based on statistical significance alone. Option C suggests that both measures of effect size are large, but this is not a necessary conclusion based on statistical significance alone.

If a Repeated-Measures Study Shows a Significant Difference Between Two