7.1.17

Students wanted to see if exercising (in particular doing jumping jacks) would help people memorize a list of 10 words that were read to them. They wanted to compare this with the same test of memorizing words while the subjects were sitting down.

1, Suppose you had 20 subjects participating in this study. Describe how you would conduct this study with a paired design with repeated measures.

a. Randomly assign people to sit or exercise first while doing the memorization activity. Find the sum of performances for each person.

b. Have each person sit first, and then exercise, while doing the memorization activity. Find the difference in performances for each person.

c. Randomly assign people to sit or exercise first while doing the memorization activity. Find the difference in performances for each person.

d. Have each person sit first, and then exercise, while doing the memorization activity. Find the sum of performances for each person.

2, If there is a significant difference in the number of words memorized, would you conclude thatexercising caused the difference?

a. No

b. Yes

3, Describe how you would conduct this study with an independent samples design.

a. Randomly assign people to sit or exercise first while doing the memorization activity. Find the sum of performances for each person.

b. Have each person sit first, and then exercise, while doing the memorization activity. Find the difference in performances for each person.

c. Randomly assign people to sit or exercise first while doing the memorization activity. Find the difference in performances for each person.

d. Have each person sit first, and then exercise, while doing the memorization activity. Find the sum of performances for each person.

4, If there is a significant difference in the number of words memorized, would you conclude thatexercising caused the difference?

a. No

b. Yes

5, Describe how you would conduct this study with an independent samples design.

a. Randomly assign each of the 20 people to two groups of 10, and split the set of words evenly between the two groups. Compare the average performance between the two groups.

b. Randomly assign each of the 20 people to two groups of 10, with one group exercising and the other sitting. Compare the standard deviation of performance between the two groups.

c. Randomly assign each of the 20 people to two groups of 10, and split the set of words evenly between the two groups. Compare the standard deviation of performance between the two groups.

d. Randomly assign each of the 20 people to two groups of 10, with one group exercising and the other sitting. Compare the average performance between the two groups.

6, Which design, paired with repeated measures or independent samples, would you say is more appropriate for this study?

a. Independent samples, because there is probably very little person-to-person variability in memorization ability.

b. Paired with repeated measures, because there is probably quite a bit of person-to-person variability in memorization ability.