In a study, the dependent variable is:

• A. The variable that is changing
• B. The variable that is constant
• C. The variable used to control for bias
• D. The variable measured at baseline only

Answer: (A)

The dependent variable is the outcome that you measure to see if it changes in response to the exposure or manipulation. It’s the variable whose value depends on what you do in the study. For example, in a study testing a new drug, the dependent variable might be the change in blood pressure, because you measure it to see if the drug has an effect. A constant or controlled variable is kept steady to reduce confounding, and a variable used to control for bias is a covariate considered in analysis, not the main outcome. Baseline measurements are starting values, not the primary outcome of interest. So the variable that is changing and being measured to assess effect fits as the dependent variable.