This paper answers 10 questions from Exercise 36 of a Health Statistics Assignment. The questions revolve around determining statistical significance, the use of ANOVAs, and determining p values and probabilities. Furthermore, the paper addresses the strengths and weaknesses of particular health based studies and research designs. The paper details specific strengths and limitations with respect to sample size, study design, random assignment of participants and the challenges of conducting longitudinal research.
¶ … 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 researchers were able to conclude that the finding was significant because the Statistical value (F) had a p-value of less than .05, which is the cut-off point for significance. Consequently, they can conclude that there is a significant difference between the control and treatment groups over time.
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.
The null hypothesis is that there are no differences in mean scores. The p value for the findings is less than .05, meaning that the null hypothesis can be rejected, and that the alternative hypothesis, that there are significant differences between difficulty and mobility scores, can be accepted.
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?
Yes, this result was statistically significant, with a probability score of less than .001.
4. If the researchers had set the level of significance or ? = 0.01, would the results of p = 0.001 still be statistically significant? Provide a rationale for your answer.
Yes, the result would still be statistically significant because .001 is less than .01.
5. If F (3, 60) = 4.13, p = 0.04, and ? = 0.01, is the result statistically significant? Provide a rationale for your answer. Would the null hypothesis be accepted or rejected?
There is no statistical significance here because .04 is greater than .01. If the alpha was set to .05, then the finding would be significant. In this case, however, the null hypothesis would fail to be rejected (it is not proper to say that the null hypothesis was accepted, simply that one was unable to reject it).
6. Can ANOVA be used to test proposed relationships or predicted correlations between variables in a single group? Provide a rationale for your answer.
No, ANOVA assesses relationships within and between groups, with respect to the variance explained, but cannot test correlations or predicted associations in a single group.
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?
The sample size was 149, split into 2 separate groups.
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.
While it is a strength of the study that there was both a control and treatment group, and that participants were randomly assigned to be in one group or the other, the study is limited by the unequal sample sizes and the small overall sample. The researchers should have created equal sample sizes between the control and treatment groups. Having a larger sample would also give them a better chance of detecting any significant results that may exist.
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 results indicated that there was a significant difference between the women who received guided imagery and the control group who did not. The treatment group reported improved pain scores (F (1,26) = 4.406, p = .046). The null hypothesis, can therefore be rejected. However, a larger sample size would still be more convincing, as it could be that the effect was due to this particular sample. Additionally, it is not necessarily guided imagery that has helped, it could be some other aspect of guided imagery that is the causal factor, such as relaxation or even a placebo effect.
You’re 83% through this paper. Sign up to read the full paper.
Sign Up Now — Instant Access Already a member? Log inAlways verify citation format against your institution’s current style guide requirements.