What characterizes independent and dependent variables?

The correct choice is that the independent variable is manipulated, while the dependent variable is measured. In experimental research, the independent variable is the one that researchers change or control to test its effects on the dependent variable. It is essential in establishing cause-and-effect relationships. For instance, in a study examining how different amounts of sunlight affect plant growth, the amount of sunlight represents the independent variable since the researcher adjusts it.

The dependent variable, on the other hand, is what is observed or measured to assess the impact of the independent variable. Continuing with the plant growth example, the growth of the plants (such as their height) would be the dependent variable, as this is what the researcher measures to see how it responds to changes in sunlight. This relationship is fundamental in experiments, where manipulation of one variable allows researchers to infer changes in another variable directly linked to it. Understanding this dynamic is crucial for interpreting results and ensuring valid experimental design.