Ed wants to know if students did significantly better on a test the second time they took it. Which test of statistical significance should Ed use?
A) Cohen's d
B) Pearson r
C) an independent t test
D) a paired t test

Question

Quizplus · Accepted Answer

A paired t test is the best choice because it compares the means of two related groups (in this case, the same group of students taking the test twice) and determines if the difference between their scores is statistically significant. Cohen's d compares the means of two independent groups, Pearson r measures the strength of the linear relationship between two continuous variables, and an independent t test compares the means of two independent groups.

Ed Wants to Know If Students Did Significantly Better on a Test