How does sample variance influence the likelihood of rejecting the null hypothesis and measures of effect size such as r² and Cohen's d? A)Larger variance increases both the likelihood and measures of effect size. B)Larger variance increases the likelihood but decreases measures of effect size. C)Larger variance decreases the likelihood but increases measures of effect size. D)Larger variance decreases both the likelihood and measures of effect size.

Question

Quizplus · Accepted Answer

Larger variance decreases the precision of the data and results in a wider distribution of scores, making it more difficult to find statistically significant results. This decreases the likelihood of rejecting the null hypothesis (Type II error) and also decreases measures of effect size such as r² and Cohen's d, as the difference between groups may be overshadowed by the variability within each group. Therefore, option D is the correct answer.

How Does Sample Variance Influence the Likelihood of Rejecting the Null