The term simple experiment is an unknown terminology in psychology or any other scientific discipline. One of the simplest experiments in psychology involves two groups (control and experimental groups), one independent variable (IV), and one dependent variable (DV). The researcher than will adjust the value of IV on each group, typically IV is present in the experimental group but absent in the control group. Then the research will analyze whether or not the DV values in the experimental group significantly differ from the DV values in the control group.