How do experimental and control groups differ? Explain with the help of an example.
Experimental groups differ from control groups as independent variable manipulation occurs in an experimental group whereas it is absent in a control group. For example, in a study conducted by Latane and Darley, there were two experimental groups and one control group. The participants in the study were sent to three types of rooms.
Room 1 in which the participant was alone formed the control group. Room 2 and 3, in which two persons were present with the participant formed experimental groups.
The independent variable, in this study, was the absence or presence of other persons sitting in the room. The remaining factors in the experiment were the same for both kinds of groups. In experimental groups, two persons were present with the real participant while in the control group, participant was alone. Therefore, it can be said that the manipulated variable is absent in control group.