Independent variable manipulation role – UGC NET Question

The independent variable is the factor that the researcher deliberately manipulates or varies in an experiment in order to examine its impact on a dependent variable. It is considered the presumed “cause” in a cause–effect relationship. By changing its levels while controlling other variables, the researcher can test specific hypotheses about its influence. Therefore, the manipulated variable described in the stem is correctly called the independent variable.

Option A:
Option A, independent variable, captures the idea of a variable that is “independent” of changes in other variables within the experimental framework, because it is set by the researcher. Different groups or conditions receive different levels of this variable. Since the stem emphasises manipulation to observe effects, this option is appropriate.

Option B:
The dependent variable represents the outcome or response that is measured to see whether it changes as a result of the manipulation. It is not itself manipulated, so it does not fit the description.

Option C:
A control variable is kept constant across conditions to prevent it from confounding the relationship between independent and dependent variables. While important, it is not the variable being manipulated.

Option D:
Extraneous variables are uncontrolled factors that may influence the dependent variable unintentionally and threaten internal validity. They are neither intentionally manipulated nor central to the experiment’s main hypothesis, so they are not the right answer.