Refer to Exercise 6 on page 119 for a description of a study about walking speed.
Exercise 6
In a double-blind study, 50 older adults who had difficulty keeping their balance and/or were slow walkers were randomly assigned to one of three groups. The first group received 4 weeks of training designed to improve balance and walking speed. The second group performed the same physical training but also practiced mental tasks at the same time. They were instructed to give equal attention to the physical and mental tasks. The third group participated in the same activities as the second group but spent half the session focused on the physical tasks and half the session focused on the mental tasks. The researchers concluded that the training methods used for the second and third groups are more effective than the method used for the first group at improving walking speed when an older person is performing a mental task at the same time.
a. What are the explanatory and response variables?
b. What is the conclusion of the study? Does this mean there is causality or only an association between the two variables? Explain.
c. The researchers also concluded that only the first group increased their self-reported confidence when performing daily activities. On the basis that the researchers felt the activities (mental and physical) the second and third groups performed were much more difficult than the activities (only physical) the first group performed, what might be the reason only the first group’s confidence increased?