Exercise 36
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 is high enough at the 5% level of significance to suggest a significant difference between the control and treatment groups. The p-value 0.005 < 0.05 hence this suggests a rejection of the null hypothesis, meaning that the control and treatment groups are found to be different.
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
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6. Can ANOVA be used to test proposed relationships or predicted correlations between variables in a single group? Provide a rationale for your answer.
Yes this is one of the main functions of the ANOVA -- to say whether or not there exists a relationship or correlation between groups. Normally, if the p-value is less than the significance level there is a difference between the groups, and if the p-value is larger than the significance level there is no difference between the groups.
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?
If K = number of groups in the study, and df = K - 1 then K = df+1 = 2+1 = 3. So there are 3 groups in the study. There are N - K number of participants so N = K+147 = 3+147 = 150 participants.
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.
In my opinion, I would like to see a larger sample size. But I agree with the choice to put more participants into the intervention group rather than the control group. That is because I would be more interested in the results from the intervention group so a larger sample is appropriate, but there is still enough in the control group to play
A researcher has designed a study to test the effects of different types of individual psycho-therapy on people's levels of anxiety. She has randomly placed people into one of three groups: a behavioral treatment group, a psycho-dynamic treatment group, or a no-treatment control group. She then measures people's level of anxiety after the treatment.
10) Was the sample for this study adequately described? Provide a rationale for your answer
The study will be separated into two groups, one will be the experimental group that will receive the intervention while the control group will receive pain medication. The intervention that the
When doing any research studies, there must be enough participants to make the sample representative of the target population and to also determine an anticipated effect size. However, 120 individuals (60 men and 60 women) are also being tested in order to maintain an equal gender balance in both groups for the study.
The researcher took the data from the participants before the study started along with an informed consent form. The patients reported the data by a web-based questionnaire. 140 people were approached to participate in the survey out of which 39 never responded, 35 were excluded, 49 declined to participate and 1 died. This led the sample size of 16 and hence non-parametric test was used. Mann-Whitney U test was used to evaluate the data before the study started and then again after the study had started. The study ran for four weeks and participants were given homework assignments for each
In my study, I will gather a randomized focus group to represent the Hispanic youth population across three high school graduating classes and three college campuses entering groups of students. Since my population is Hispanic immigrant youth, my sample group will be collected in three high schools and three colleges in Hispanic neighborhoods or with a relative large population of Hispanic or Latino students. A group of 15 randomized students will be gathered from each school, to get a total of 45 high school graduating students and 45 college entering students. Making my total sample size of 90 Hispanic students.
Types of Participants. There was a total of 768 participants in the thirteen studies. Table 1 provides detailed information on participants in each individual study.
In other words, the p-value (p=0.003) included in Figure 3 was from testing whether 107.32–110.19 = –2.87 in PA was significantly different from 111.68-110.95=0.73 in PA-P. Therefore, our results were correctly reported in the submitted manuscript. In order to clarify the interpretation, we have now modified the paragraph and included the revised sentences in Page 9 such as
What kind of data was presented in the results section? Were there averages (means), correlations, or statistical tests?
ANOVA is simply an analysis of variance measure in statistics that is used to compare the means, or average, of more than two groups. It tests for significant differences, or differences that are large enough to effect or change the study outcomes. It analyzes variances between and within the study groups and can test several null hypothesis, or claims being tested, at the same time. It is also used to compare the variances between the group members as well as between the individual sample groups.
-refer back to significance. What do I want to accomplish with the results of this study.
This study was a single-blind and randomized controlled design in which the patients had to meet very specific criteria in order to be eligible for the study. The patients who met the criteria were recruited from two community mental health centers. After baseline testing, participants were randomly al-located in the order in which they were enrolled into the study to participate in either AE (aerobic exercise) or a stretching and toning control group. The participants had to go through
Size of the sample group is needed to be specified properly due to the goal is to make inferences about the population from the sample. The appropriate sample size can be resulted in terms of the reliability of the study, especially empirical study. Therefore, how many samples can satisfy the target? In addition, a smaller sample size leads to a higher error of the sampling when compared with a bigger size. Even if an increasing of sample size can diminish the error, after it goes beyond some point, an error cannot be decreased significantly (see figure 4.1). Furthermore, an optimal sample size can also save time and cost of study.
on the relationship between a dependent and independent variables. It is a combination of an ANOVA test and reg
Sample size calculation: To determine the sample size needed for all groups, an a priori power analysis, conducted using G*Power 3.0.10 software, calculated the required sample size n = 30 per group bases on an ANOVA test that has 80% power to detect a significant