Doctors identify "chronic tension-
type headaches" as headaches that occur almost
daily for at least six months. Can antidepressant med-
ications or stress management training reduce the
number and severity of these headaches? Are both to-
gether more effective than either alone? Researchers
want to compare four treatments: antidepressant
alone, placebo alone, antidepressant plus stress
management, and placebo plus stress management.
Describe a completely randomized design involving
36 headache sufferers who are willing to participate
in this experiment. Write a few sentences describing
how you would implement your design.