Discuss

what each aspect of this result means: *F*_{(1, 26)} = 4.406, *p*

= 0.046.

4.Is

the change in the pain scores after 12 weeks of guided imagery statistically

significant for the intervention group? If yes, at what probability?

5.State

the null hypothesis for the effect of guided imagery on pain scores for the

subjects in the treatment group at 12 weeks. Should this null hypothesis be

accepted or rejected? Provide a rationale for your answer.

6.How

many means are being compared for the pain scores at 12 weeks?

7.What

did the researcher set the level of significance or alpha (a) at for this

study? When will study results be considered significant?

8.The

researchers do not report the standard deviations associated with the means.

Would you be interested in knowing the standard deviations? Provide a rationale

for your answer.

ANSWERS

TO STUDY QUESTIONS

1.A

repeated-measures ANOVA was conducted to examine differences between the

intervention group, receiving the treatment of GI and the control group over 12

weeks. The groups were examined for differences for the dependent variables of

pain and mobility over the 12-week time period. The repeated-measures ANOVA was

appropriate since the focus was on examining group differences over time. In

addition, the groups were independent due to random group assignment, and the

dependent variables (pain and mobility) were measured at least at the interval

level of measurement.

2.According

toFigure 1, the average pain scores for

the guided imagery intervention group and the control group were most similar

at baseline. This is what the researchers would hope for, since they had a

sample of 28 subjects who were randomly assigned to the treatment and control

groups to promote similarity of the groups at the start of the study. Thus if a

change occurred between the two groups during the study, it is assumed it is

due to the treatment and not because the groups were different at the start of

the study.

3.*F*_{(1,26)} *=* 4.406, *p* = 0.046, where *F* is the statistic for

ANOVA and the group *df* = 1 and the error *df* = 26. The *F*

ratio or value = 4.406, which is significant at *p* = 0.046

4.Yes,*F*_{(1, 26)} *=* 4.406, *p* = 0.046 is statistically

significant at *p* = 0.046. The level of significance for this study was

set at a = 0.05, and since *p* is

5.The

null hypothesis is: Women with OA receiving guided imagery have no greater

improvement in their pain scores than those in the control group at 12 weeks.

The study results indicated a significant improvement in the pain scores of

women with OA who received the treatment of guided imagery (*F*_{(1,26)} *=* 4.406, *p* = 0.046). Thus, the null hypothesis was

rejected.

6.Two

means are being compared at 12 weeks. The mean of the control group and the

mean of the guided imagery group for pain are being compared at 12 weeks.

7.The

researchers set the level of significance or alpha (a) = 0.05, which means that

any results with a *p* (probability) of = 0.05 will be considered

significant.

8.Answers

may vary, but it would be helpful to include the standard deviations with the

means since the standard deviations indicate the spread of the scores for the

two groups. The standard deviations for the treatment and control groups also

are needed to calculate the effect size or the effect of the treatment in a

study. The effect size is needed to conduct a power analysis to predict the

sample size needed for future studies. In addition, if the results from this

study were to be combined with the results from other studies, the means and

standard deviations for the treatment and control groups are needed to conduct

a meta-analysis to combine study results to determine current knowledge in an

area. In summary, it is helpful to report all means and standard deviations for

study variables whether the results are significant or nonsignificant, because

they are valuable to consider in conducting future research and meta-analyses.

Name:____________________________________________

Class: ____________________

Date:

_________________________________________________________________________________

? EXERCISE 36 Questions to be Graded

1.The

researchers found a significant difference between the two groups (control and

treatment) for change in mobility of the women with osteoarthritis (OA) over 12

weeks with the results of *F*_{(1, 22)} = 9.619, *p* = 0.005.

Discuss each aspect of these results.

2.State

the null hypothesis for the Baird and Sands (2004) study that focuses on the

effect of the GI with PMR treatment on patients’ mobility level. Should the

null hypothesis be rejected for the difference between the two groups in change

in mobility scores over 12 weeks? Provide a rationale for your answer.

3.The

researchers stated that the participants in the intervention group reported a

reduction in mobility difficulty at week 12. Was this result statistically

significant, and if so at what probability?

4.If

the researchers had set the level of significance or a = 0.01, would the

results of *p* = 0.001 still be statistically significant? Provide a

rationale for your answer.

5.If*F*_{(3, 60)} = 4.13, *p* = 0.04, and a = 0.01, is the result

statistically significant? Provide a rationale for your answer. Would the null

hypothesis be accepted or rejected?

6.Can

ANOVA be used to test proposed relationships or predicted correlations between

variables in a single group? Provide a rationale for your answer.

7.If

a study had a result of *F*_{(2, 147)} = 4.56, *p* = 0.003,

how many groups were in the study, and what was the sample size?

8.The

researchers state that the sample for their study was 28 women with a diagnosis

of OA, and that 18 were randomly assigned to the intervention group and 10 were

randomly assigned to the control group. Discuss the study strengths and/or

weaknesses in this statement.

9.In

your opinion, have the researchers established that guided imagery (GI) with

progressive muscle relaxation (PMR) reduces pain and decreases mobility

difficulties in women with OA?

10.The

researchers stated that this was a 12-week longitudinal, randomized clinical

trial pilot study with 28 women over 65 years of age with the diagnosis of OA.

What are some of the possible problems or limitations that might occur with

this type of study?

(Grove 267)

Grove, Susan K.. *Statistics for Health CareResearch: A Practical Workbook*. W.B. Saunders Company, 022007.

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