Your CEO has followed your advice and now wants you to measure effect sizes. You report a Pearson's r of 0.50 for the impact of Power Nylon shorts on athletic performance times. Your CEO wants to know if this is bad, as she remembers that a p-value of 0.30 is not good. What do you tell her?
A) You tell her that effect size and p-values are the same and that a Pearson's r of 0.50 means there is no statistically significant effect. Power Nylon shorts should cease production.
B) You tell her that effect size and p-values are not the same and that a Pearson's r of 0.50 is a large effect, suggesting she should roll-out the launch of Power Nylon shorts.
C) You tell her that effect size and p-values are not the same and that a Pearson's r of 0.50 is a small effect, suggesting she should stop the launch of Power Nylon shorts until more data analysis is done.
D) You tell her that effect size and p-values are not the same and that a Pearson's r of 0.50 is a medium effect, suggesting she should roll-out the launch of Power Nylon shorts.

Question

Quizplus · Accepted Answer

Effect size and p-values are not the same thing. A Pearson's r of 0.50 is a large effect size. It means that there is a significant positive correlation between wearing Power Nylon shorts and better athletic performance times. The p-value only tells us if the correlation is statistically significant, which means it is unlikely to have occurred by chance alone. Therefore, the CEO should roll-out the launch of Power Nylon shorts.

Your CEO Has Followed Your Advice and Now Wants You