After reading Martin's ( 2002) article on the potential benefits of laughter, a group of student researchers decided to test the hypothesis that laughter increases pain tolerance. To test this hypothesis, they randomly assigned 60 subjects to one of two conditions. In the " laughter" condition, subjects watched a humorous videotape. The control group watched an action adventure videotape. While watching the videotape, subjects were asked, one at a time, to keep their hands in a bucket of ice water for as long as they could. The students recorded the amount of time each subject kept his or her hands in the ice water.
a. Which statistical methods discussed in this chapter were used in this study?
b. Identify the independent variable manipulated by the student researchers.
c. Identify the dependent variable measured.
d. Explain why this study is an experiment.
e. Explain why statistical hypothesis testing is necessary in this experiment.