Why is it important to only change one independent variable during a test?

Changing only one independent variable during a test is crucial because it helps isolate the effects of that variable on the dependent variable. This ensures that any observed changes can be attributed directly to the manipulation of the independent variable, rather than being confounded by other variables. By maintaining control over other factors, researchers can draw clearer, more valid conclusions about cause and effect. This practice enhances the reliability and reproducibility of experimental results.