What does an independent variable represent in an experiment?

In an experiment, the independent variable represents the factor that is intentionally changed or manipulated by the researcher to observe its effect on other variables. This is key in experimental design because it allows researchers to determine whether there is a cause-and-effect relationship between the independent variable and the dependent variable, which is the factor that is measured as a response. By altering the independent variable, researchers can isolate its influence and assess how it affects the outcome of the experiment. This is fundamental for drawing valid conclusions from experimental data. Understanding the role of the independent variable is critical to the scientific method, as it is the basis for hypothesis testing and experimentation.