You carried out a study where you tested the effectiveness of a new therapy technique at reducing anxiety.You identified a group of high-anxiety individuals,and you measured their anxiety before therapy,immediately after therapy,and at two follow-up sessions 1 month and 2 months after the therapy is concluded.High scores on the anxiety measure are scaled to reflect relatively higher levels of anxiety.Here is the hypothetical data from SPSS output.

According to the main ANOVA analysis,how should the results be described (assume an alpha level of .05)?
A)The effect of the new therapy technique was statistically significant but its effect size was weak.
B)The effect of the new therapy technique was statistically significant and the effect size was strong.
C)The effect of the new therapy technique was not statistically significant,but the size of the effect suggests this may be due to low power.

Question

You carried out a study where you tested the effectiveness of a new therapy technique at reducing anxiety.You identified a group of high-anxiety individuals,and you measured their anxiety before therapy,immediately after therapy,and at two follow-up sessions 1 month and 2 months after the therapy is concluded.High scores on the anxiety measure are scaled to reflect relatively higher levels of anxiety.Here is the hypothetical data from SPSS output.  
 
According to the main ANOVA analysis,how should the results be described (assume an alpha level of .05)?
A)The effect of the new therapy technique was statistically significant but its effect size was weak. 
B)The effect of the new therapy technique was statistically significant and the effect size was strong. 
C)The effect of the new therapy technique was not statistically significant,but the size of the effect suggests this may be due to low power.

Quizplus · Accepted Answer

The output shows a significant effect of time (p < .001), a significant interaction between time and group (p = .006), and a non-significant main effect of group (p = .13). This suggests that the therapy technique had a significant effect on reducing anxiety over time, with the effect being stronger for the treatment group compared to the control group (as shown by the interaction effect). Furthermore, the effect size of the intervention can be evaluated using the partial eta-squared statistic, which is .22 for the interaction effect. This indicates a large effect size, suggesting that the therapy technique had a strong impact on reducing anxiety levels in high-anxiety individuals.

You Carried Out a Study Where You Tested the Effectiveness