Which term describes the factor that a researcher monitors to determine the effect of the experimental treatment?

• A. The independent variable
• B. The constant
• C. The dependent variable
• D. The control variable

Answer: (B)

The key idea is identifying what you measure to see the treatment’s effect. The factor you monitor is the dependent variable—the outcome that changes in response to the experimental treatment. You deliberately change another factor, the independent variable, to test its effect. Constants are things you keep the same to prevent extra influences, and control variables are specific constants you manage to reduce confounding. For example, in testing a fertilizer, the amount of fertilizer is the independent variable, plant growth is the dependent variable, and soil type or light are control variables to keep conditions consistent. So the monitored outcome described here is the dependent variable.