The experimental research strategy is intended to answer cause-and-effect
questions about the relationship between two variables. For example, are increases
in exercise responsible for causing decreases in cholesterol level? To
answer the question, a researcher could create two treatment conditions by
changing the amount of exercise from low in one condition to high in the
other. Then, one group of individuals is assigned to the low-exercise condition
and a similar group is assigned to the high-exercise condition. Cholesterol is
measured for each group and the scores in the low-exercise condition are
compared with the scores in the high-exercise condition to determine whether
changes in the level of exercise cause changes in cholesterol (Table 6.2a). Note
that the purpose of the experimental research strategy is to explain the relationship
by determining the underlying cause. An experimental study is conducted
with rigorous control to help ensure an unambiguous demonstration of
a cause-and-effect relationship. In Chapter 7 the details of the experimental
research strategy are discussed.