Which type of variable is tested in order to observe an effect in an experiment?

The independent variable is the factor that is manipulated or changed by the experimenter to observe its effect on another variable. In an experiment, researchers alter the independent variable to see how it influences the dependent variable. This relationship is critical as it helps establish cause-and-effect dynamics.

For instance, if an experiment is designed to study the impact of different amounts of sunlight on plant growth, the amount of sunlight is the independent variable. The experimenter changes this variable to observe how it affects the growth of the plants, which is measured and thus becomes the dependent variable.

Understanding the role of the independent variable is essential as it allows researchers to make conclusions about the influence of specific factors within their experimental design.