What Is a controlled exp erement?

A controlled experiment is a scientific investigation in which one variable is manipulated while all other variables are kept constant to isolate the effects of the manipulated variable. This design allows researchers to establish cause-and-effect relationships by comparing results between a control group and an experimental group. By controlling external factors, the experimenter can ensure that any observed changes can be attributed to the variable being tested. This method is fundamental in fields such as Biology, chemistry, and psychology for validating hypotheses.