Question: Two methods of memorizing difficult material are being tested to determine if one method produces better retention. Nine pairs of students are included in the study. Each student in the pair has been matched according to IQ and academic background and then randomly assigned to use one of the two methods: Method A or Method B. A memorization test is given to all the students where the final score can range from 0 to 100 points.

Table A4. Memorization Methods

a. The two samples are which of the following: two independent or matched pairs? Explain.

b. What type of study is found—observational or randomized experiment? Explain.

c. What is the experimental unit?

d. What is the response variable?

e. What is the explanatory variable?

f. What confidence interval(s) from Table A4 should be used to compare the memorization score for the two methods? Explain.

g. Using your answer in the previous part as your basis, state an appropriate conclusion in terms of the problem.