Controlled experiments are essential for what scientific purpose?

Controlled experiments are vital in science primarily to establish a cause-and-effect relationship between variables. In a controlled setting, scientists manipulate one independent variable while keeping others constant. This allows researchers to determine how changes in the independent variable directly affect the dependent variable. By isolating these variables, controlled experiments minimize the impact of external factors, making it clearer which changes are responsible for any observed effects.

Establishing a cause-and-effect relationship is crucial because it helps scientists understand the mechanisms behind a phenomenon, formulate theories, and predict outcomes in real-world applications. This systematic approach ensures results are reliable and valid, hence strengthening the overall scientific understanding of a particular process or event.