Dunn et al. (2005) conducted an experiment of the relationship between exercise and depression. Participants were randomly assigned to either a low or a high intensity workout regime. Some were assigned to work out 3 days a week, while other participants worked out 5 days a week. Identify the independent variable(s) in this studyA) the participants' interest in exercise and health conditionsB) the amount of exercise and frequency of exerciseC) depressionD) energy condition

The independent variable refers to the variable that can be controlled in the experiment to test how this variable has an effect on the dependent variable.

The dependent variable is the variable that is being measure and that the researchers have no real control in. This variable will be affected by the manipulation of the independent variable.

In this example, the researchers want to study the relationship between exercise and depression. They assign participants to different groups, these groups differ on the intensity of the workout regime and the frequency of the workout. We can see that the researchers can manipulate the amount of exercise and the frequency the participants workout, they want to see how these regimes will have an effect on the depression the participants experiment. Thus, we can see that the independent variable, which is controlled and will have an effect on the other variable, is the amount of exercise and frequency of exercise.