1. What demographic variables were measured at the interval level of measurements? Age, Income, Length of labor, Return to work and number of hours working per week. 2. What statistics were used to describe the length of labor in this study? Mean and standard deviation were used to describe the length of labor. These were appropriate since mean and standard deviation can be calculated on an interval level of measurement. 3. What other statistics could have been used to describe the length of labor? Provide a rationale for your answer? Range could also be used to describe the length of labor since this statistic can be used on interval data with no natural zero point. 4. Were the distributions of scores similar for the experimental and control groups for the length of labor? Provide a rationale for your answer. The distribution of scores was similar for the experimental and control groups for length of labor. The experimental group had a mean of 14.63 hours and the control group had a mean of 12.79 hours which is a difference of less than 2 hours with a SD of 7.78 for experimental and 7.2 for control.

5. Were the experimental and the control groups similar in their type of feeding? Provide a rationale for your answer. The experimental and control groups were similar in the type of feeding. More people fed with a bottle than breast or breast and bottle in the experimental and control group. The percentages in both were lowest for breast and bottle with 6.3% for experimental and 5.6% for control. 6. What was the marital status mode for the subjects in the experimental and control groups? Provide both frequency and percentage for the marital status mode for both groups. Married was the marital status mode for the experimental group and control group since it was the largest group. The frequency and percentage are 25 and 78.1% for the experimental group and 31 and 86.1% for the control group who are married

7. Could a median be determined for the education data? If so, what would the median be for education for experimental and the control groups? Provide a rationale for your answer. Yes, a median can be determined for the educational data. The median for the experimental and the control group are the people in the some college group. The median is the “middle” category and can be determined for ordinal data like education. 8. Can the findings from this study be generalized to black women? Provide a rational for your answer. The findings from this study cannot be generalized to Black women since the sample size is so low in the experimental group and there are no Black women in the control group. Black women might have different self- care interventions to manage post- partum fatigue than white women.

9. If there were 32 subjects in the experimental group and 36 subjects in the control group, why is the income data only reported for 30 subjects in the experimental group and 34 subjects in the control group? There is a note at the bottom of the table that mentions that there is missing data. Perhaps some mothers did not reveal that data. 10. Was the sample for the study adequately described? Provide a rationale for your answer. The sample was adequately described. However, adding information about any complications before or during births, the type of delivery for example C-section vs. natural, or if the women had any help such as a nanny would add to the description.

Exercise 16: Mean and Standard Deviation

1. The researchers analyzed the data they collected as though it were at what level of measurement?

a. Nominal

b. Ordinal

c. Interval/ratio

d. Experimental

Answer: c. The researchers analyzed the data as though it were at the interval/ratio level since they calculated means (the measure of central tendency that is appropriate only for interval/ratio level data) and standard deviations (the measure of dispersion for interval/ratio data) to describe their study variables.

2. What was the mean posttest empowerment score for the control group? Answer: Mean = 97.12.

3. Compare the mean baseline and posttest depression scores of the experimental group. Was this an expected finding? Provide a rationale for your answer. Answer: The experimental group subjects scored lower on the depression posttest (mean = 13.36 vs. the baseline score of mean = 14.00), meaning that they were less depressed after the completion of the empowerment program. This was an expected finding, because the researchers hypothesized that the empowerment program would be beneficial to ESRD patients and result in a decrease in their depression scores. However, the difference in the depression baseline and posttest means for the experimental group was only 0.64, which is less than what might have been expected.

4. Compare the mean baseline and posttest depression scores of the control group. Do these scores strengthen or weaken the validity of the research results? Provide a rationale for your answer. Answer: The mean baseline and posttest depression scores of the control group were identical. Both means equaled 10.40, which indicate that there was no change in the level of depression of the control group subjects from baseline to posttest. This result strengthens the validity of the study findings, indicating that the empowerment program resulted in a decrease in the depression scores for the experimental group.

5. Which group’s test scores had the least amount of variability or dispersion? Provide a rationale for your answer. Answer: The experimental group’s empowerment posttest scores had the smallest amount of dispersion or variability, as indicated by the smallest SD of 7.28.

6. Did the empowerment variable or self-care self-efficacy variable demonstrate the greatest amount of dispersion? Provide a rationale for your answer. Answer: The experimental group’s baseline self-care self-efficacy scores had the greatest dispersion as evidenced by the largest SD of 14.88.

7. The mean (X) is a measure of ________________ __________________ of a distribution while the SD is a measure of _____________________ of its scores. Both X and SD is _________________ statistics.

Answer: The mean (X) is a measure of central tendency of a distribution while SD is a measure of dispersion of its scores. Both X and SD is descriptive statistics.

8. What was the mean severity for renal disease for the research subjects? What was the dispersion or variability of the renal disease severity scores? Did the severity scores vary significantly between the control and the experimental groups? Is this important? Provide a rationale for your answer.

Answer: The mean severity score for renal disease was 6.74 and was provided in the Relevant Study Results. The dispersion of the renal disease severity scores was SD = 2.97, with the range of severity scores being 0–10. There was no significant difference in renal disease severity scores for the control and the experimental groups as indicated in the Relevant Study Results. It is important to indicate that the research subjects were similar in demographic characteristics at the start of the study, and the differences noted in the study variables are assumed to be due to the treatment and not to differences in the groups at the start of the study.

9. Which variable was least affected by the empowerment program? Provide a rationale for your answer. Answer: The subjects’ mean or average depression scores showed the least change as compared to their baseline values (only 0.64 points as compared to 6.64 points for empowerment and 6.44 points for self-care self-efficacy). However, it is important to note that the mean score for the depression scale was lower than for the empowerment and self-care self-efficacy scales.

10. Was it important for the researchers to include the total means and SDs for the study variables in Table 2 to promote the readers’ understanding of the study results? Provide a rationale for your answer.

Answer: No, it was not important to the readers’ understanding to have the total means and SDs for the study variables. The main focus of the table was to describe (using X and SD) the study variables for the experimental and control groups. Although it is interesting to have the total sample means and SDs, these do not add to the overall understanding of the information presented in this study. These total means and SDs for study variables are not useful in determining sample size for future studies or for conducting meta-analyses of several studies’ results.