In experimental design, the variable that is deliberately changed by the researcher to observe its effect is called the

• A. Independent Variable
• B. Dependent Variable
• C. Control Variable
• D. Confounding Variable

Answer: (A)

In experimental design, the independent variable is the factor deliberately changed by the researcher to observe its effect. It is the manipulated condition or dose you set at different levels to see how the outcome responds. For example, if you want to know whether study time affects test scores, the amount of time spent studying is the independent variable, while the test score is the dependent variable—the outcome you measure to determine the effect.

Control variables are kept constant across all conditions so they don’t influence the results, like keeping the testing environment the same for everyone. A confounding variable is any other factor that varies with the independent variable and could explain changes in the dependent variable, potentially clouding the true effect; researchers try to minimize this through design choices or randomization.

So the variable you deliberately manipulate to observe its impact is the independent variable.