Assignment
Question 1
Explain the importance of random sampling. What problems/limitations could prevent a truly random sampling and how can they be prevented?
Question 2
Explain each sampling technique discussed in the "Visual Learner: Statistics" in your own words, and give examples of when each technique would be appropriate.
EXERCISE 1
What are the assumptions for conducting a paired or dependent samples t -test in a study? Which of these assumptions do you think were met by the Lindseth et al. (2014) study?
1. In the introduction, Lindseth et al. (2014) described a "2-week washout between diets." What does this mean? Why is this important?
2. What is the paired t -test value for mood (irritability) between the participants ' consumption of high- versus low-aspartame diets? Is this result statistically signi?cant? Provide a rationale for your answer.
3. State the null hypothesis for mood (irritability) that was tested in this study. Was this hypothesis accepted or rejected? Provide a rationale for your answer.
4. Which t value in Table 2 represents the greatest relative or standardized difference between the high- and low-aspartame diets? Is this t value statistically signi?cant? Provide a rationale for your answer.
5. Discuss why the larger t values are more likely to be statistically signi?cant.
6. Discuss the meaning of the results regarding depression for this study. What is the clinical importance of this result?
7. What is the smallest, paired t -test value in Table 2? Why do you think the smaller t values are not statistically signi?cant?
8. Discuss the clinical importance of these study results about the consumption of aspartame. Document your answer with a relevant source.
9. Are these study ?ndings related to the consumption of high- and low-aspartame diets ready for implementation in practice? Provide a rationale for your answer.