A researcher conducts an experiment to determine whether moderate doses of St. Johns Wort have any effect of memory for college students. For this study, what is the independent variable?

Question

a.
The memory score for each participant.

b.
Cannot answer without more information.

c.
The amount of St. Johns Wort given to each participant.

d.
The group of college students.

Answer 1

The independent variable in this study is:

c. The amount of St. Johns Wort given to each participant.

The independent variable is the one that is manipulated or controlled by the researcher to observe its effects on the dependent variable, which in this case is the memory score for each participant.