Experimental design is a structured approach used in research to test hypotheses and determine cause-and-effect relationships. It involves planning how to conduct an experiment, including selecting participants, defining variables, and deciding on methods for data collection. A well-designed experiment helps ensure that results are valid and reliable. Key components of experimental design include the control group, which does not receive the treatment, and the experimental group, which does. Randomization is often used to assign participants to these groups, minimizing bias. By carefully controlling variables, researchers can draw meaningful conclusions about the effects of the independent variable on the dependent variable.