If a correlated-groups t-test and an independent-groups t-test both have df=16,which experiment used more participants?
A)they both used the same number of participants (n=18)
B)they both used the same number of participants (n=17)
C)the correlated-groups t-test
D)the independent-groups t-test

Question

Quizplus · Accepted Answer

In both types of t-tests, df is calculated as (n1 + n2) - 2. Therefore, if df=16, we can solve for the total number of participants by rearranging the formula to n1 + n2 = (df+2). Since the independent-groups t-test involves two separate groups with no relationship (correlation) between them, it is likely that each group had a smaller size than the single group used in the correlated-groups t-test. Therefore, it is more likely that the independent-groups t-test used more participants in total to achieve the same df value.

If a Correlated-Groups T-Test and an Independent-Groups T-Test Both Have