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. * The F-value suggests that there is a significant difference between the results of the control and treatment groups. The P-value of 0.005 is < the alpha of 0.05. This suggest that the groups are significantly different and the null hypothesis should be rejected. 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. * Treatment group mean = control group mean
* With the p-value being < the alpha, the null hypothesis would be rejected indicating the difference in the mean mobility scores. 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? * The p-value of 0.005 suggests that the results are statistically significant. 4. If the researchers had set the level of significance or α = 0.01, would the results of p = 0.001 still be statistically significant? Provide a rationale for your answer. * Yes, 0.001 is the α of 0.01, the null hypothesis would be accepted.
6. Can ANOVA be used to test proposed relationships or predicted correlations between variables in a single group? Provide a rationale for your answer. * ANOVA tests differences in relationships among and within groups. To do this, the test requires more than one sample group. ANOVA cannot be used in this situation. 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? * There were two groups with a sample size of 149
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. * Strength: The use of an
experimental group and a control group with which to compare data. * Weakness: The limited size of the sample. A larger sample size would add credibility to the study. 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? * The study results show a significant improvement in the pain score of the women that underwent the guided imagery treatment.
We rejected the null hypothesis that stated the interventional and control group means are equal. The result of the study show that the two groups are in fact significantly different. 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? * The limited sample size is a possible problem. Also, the use of longitudinal study tends to follow a subject for a very long period of time. Possibly decades. This type of study is generally used in psychology and sociology studies. Perhaps, a cross sectional study would be more appropriate as it makes comparisons of individuals with like characteristics.