Question

A sleep researcher conducts a memory test on people after they have either 1) dreamed the night before, or 2) not dreamed. She reads them a list of 40 words, and asks them to recall them after a 1 minute break. The number of recalled words is presented below

Participant	After Dreaming	After Not Dreaming
Abe	12	11
Bev	15	14
Cal	9	7
Dan	13	19
Eve	25	10
Fay	18	8
Guy	14	14
Hal	16	13
Ike	19	12

Is there a difference in the number of words recalled after dreaming? What is the size of the effect?

Answer 1

H0: There is no difference in the number of words recalled after dreaming

H1: There is difference in the number of words recalled after dreaming

From the given data

After Dreaming	After Not Dreaming	Difference
12	11	1
15	14	1
9	7	2
13	19	-6
25	10	15
18	8	10
14	14	0
16	13	3
19	12	7

Test Statstiic t = 3.67 / (6.16/sqrt(9)) = 1.7873

Critical t: ±2.3060
P-Value: 0.1122

Here t value is in t critical value and P-value > alpha 0.05 so we accept H0

thus we conclude that there is no difference in the number of words recalled after dreaming