Participants threw darts at a target In one condition they u

Participants threw darts at a target. In one condition, they used their preferred

hand; in the other condition, they used their other hand. All subjects performed in

both conditions (the order of conditions was counterbalanced). Their scores are

shown below.

Preferred        Non-preferred

12                    7

7                      9

11                    8

13                   10

10                    9

a. Which kind of t-test should be used?

b. Calculate the two-tailed t and p values using this t test.

c. Calculate the one-tailed t and p values using this t test.

Solution

a) Paired t-test because the values from the preferred and non-preferred trials are from the same participants.

Using Microsoft Excel: =ttest(array1, array2, tails, type) --- tails: 1 or 2, type: paired (1)

b) =ttest(preffered,nonpreferred,2,1)=0.166=p value

c) =ttest(preferred,nonpreferred,1,1)=0.083=p value