Solutions- experimental group is the one in which the participants are exposed to the independent variable manipulation.
Control group is used for comparison purpose , in each way its like the experimental group but the independent variable manipulation is absent in it.
For example – if the researcher is observing the violence imitation by children.
So children are randomly assidgned into two groups and are placed in 2 rooms that are alike in all senses .
Both rooms have a bobo doll and children are observed without being noticed
In experimental group – a model entres the room and violently behave with the dool and exits while in the control group nothing such is done. When children are left alone with the bobo dolls the experimental group children tend to be more aggressive than the control group. This is a classic example of observational method adopted by famous psychologist bandura.