Question

A researcher would like to determine if relaxation training will affect the number of headaches for chronic headache sufferers (n = 8). A week before training, each participant recorded the number of headaches experienced. Participants then receive relaxation training and following training the number of headaches were recorded again. The following results were provided:

• ΣD = -16
• SS = 14

Determine whether the results indicate a significant difference in chronic headaches after relaxation training? Use an alpha .05, level of significance. type the hypotheses (words or notation), critical boundary, standard error, t-score and decision including notation, decision and an explanation why.

Calculate Cohen’s d if appropriate

Answer 1

H0:Null Hypothesis: =0 (There is no significant difference in chronic headaches after relaxation training)

HA;Alternative Hypothesis: 0 (There is a significant difference in chronic headaches after relaxation training) (Claim)

n = 8

= - 16/8 = - 2

SE = s_d/

= 1.4142/

= 0.50

Standard Error = 0.50

Test Statistic is given by:

= - 2/0.50

=- 4.00

So,

t score = - 4.00

=0.05

df = 8 - 1 = 7

From Table, critical values of t = 2.3646

Critical Boundary: t = 2.3646

Since calculated value of t = - 4.00 isless than critical value of t =- 2.3646, the difference is significant. Reject nulll hypothesis.

Conclusion:
The data support the claim that there is a significant difference in chronic headaches after relaxation training.

Cohen's d is given by:

So,

Cohen's d = - 1.4142

Answers to questions asked:

(1)

H0:Null Hypothesis: =0 (There is no significant difference in chronic headaches after relaxation training)

HA;Alternative Hypothesis: 0 (There is a significant difference in chronic headaches after relaxation training) (Claim)

(2)

Critical Boundary: t = 2.3646

(3)

Standard Error = 0.50

(4)

t score = - 4.00

(5)

Since calculated value of t = - 4.00 isless than critical value of t =- 2.3646, the difference is significant. Reject nulll hypothesis.

(6)

The data support the claim that there is a significant difference in chronic headaches after relaxation training.

(7)

Cohen's d = - 1.4142