Why are experimental investigations the best type of scientific investigation to demonstrate cause-and-effect relationships?

Answer:

Experimental investigations are the best type of scientific investigation to demonstrate causeandeffect relationships because they allow the investigator to actively manipulate variables and control conditions. The independent variable can be isolated and manipulated, producing a change (or no change) in the dependent variable. This change can be measured to gather evidence to support or refute the causeandeffect relationship. Experimental investigations also use a control group (a group that does not receive the factor being tested) for comparison.