In a study designed to test a new antidepressant, a large number of outpatient psychiatric patients were randomly assigned to one of two groups. One of the groups was given the drug as a pill. The other group was given identical-looking inert pills. All participants were tested in the morning. The level of depression of each subject was measured by three psychologists independently, using the Beck Depression Inventory. Which was the independent variable in this study?

Question

Quizplus · Accepted Answer

The independent variable is the factor that is intentionally manipulated by the researcher, which in this case is the drug being administered to the participants. The assignment of participants to groups is also a factor that is manipulated by the researcher, but it is not the main focus of the study and is more of a procedural detail. The level of agitation and the Beck Depression Inventory are both measures of the dependent variable, which is the outcome variable that is affected by the independent variable.

In a Study Designed to Test a New Antidepressant, a Large