What defines the independent variable in an experiment?

The independent variable in an experiment is defined as the factor that is deliberately changed by the experimenter to observe its effects on other variables. This change is made to test a hypothesis and determine whether this variable has an impact on the dependent variable, which is the outcome that is measured in response to changes in the independent variable. By manipulating the independent variable, researchers can establish cause-and-effect relationships within their experimental design.

For instance, if a scientist wants to study the effect of light on plant growth, the amount of light that is given to the plants would be the independent variable. This is what the researcher changes to observe how it affects the growth of the plants, which would be the dependent variable. Understanding this distinction is fundamental to designing experiments and interpreting data correctly.