Question

An educational psychologist has developed a mediation technique to reduce anxiety. The psychologist selected a sample of high anxiety students that are asked to do the mediation at two therapy sessions a week apart. The participants' anxiety is measured the week before the first session and at each subsequent session. Below are the anxiety scores for the participants. What can the psychologist conclude with α= 0.05?

before	session 1	session 2
9 6 8 5 8 6 9 6 8	7 7 6 7 1 9 7 7 7	6 5 5 4 5 6 5 5 4

a) What is the appropriate test statistic?
---Select--- na one-way ANOVA within-subjects ANOVA two-way ANOVA  

b) Compute the appropriate test statistic(s) to make a decision about H₀.
critical value =   ; test statistic =  

Compute the corresponding effect size(s) and indicate magnitude(s).
η² =   ;  ---Select--- na trivial effect small effect medium effect large effect

Conduct Scheffe's Post Hoc Test for the following comparisons:
1 vs. 3: test statistic =   ; significant:  ---Select--- Yes No  
2 vs. 3: test statistic =   ; significant:  ---Select--- Yes No  

Answer 1

A)The appropriate test statistic is one way ANOVA

B)Critical value : F_(2,24,.05)= 3.4

Test Statistic : F= 4.595

Decision : Reject H₀

Effect size

=22.889/82.667= .2769

Magnitude : Medium effect

Scheffe Test

1 vs 3, difference = 2.22 ; significance : Significant

2vs 3, difference = 1.44; significance :not significant