Dr. Jones conducts an experiment investigating the effects of distraction on memory. A list of 40 two-syllable words is prepared. Dr. Jones obtains a sample of 50 students, all between the ages of 18 and 22, and presents the list of words to the entire group. Then each individual is randomly assigned to one of two groups. One group of participants is given a memory test for the list of words in a quiet room, and the second group is tested in a room with loud construction noises (hammering, sawing, and so on) in the background.
a. Identify the independent variable and the dependent variable in this study.
b. Explain why Dr. Jones can be reasonably confident that the participants' age is not a confounding variable. That is, explain why it is unlikely that one group does better on the memory task because they are substantially older than the other group.
c. Although personality varies from one participant to another, Dr. Jones is probably not worried about personality as a confounding variable. Explain why not.