What is it and When do we use it?

A two-group experimental design is when a researcher divides the subjects into two groups and compares their results. One of the groups is a control group which does not get the treatment, the other is the treatment or experimental group that does get the treatment. There is also the possibility of multiple treatment groups. Ideally suited for testing the effects of a single independent variable that can be manipulated as a treatment.

(Bhattacherjee, 2012)

Treatment manipulation is the selected intervention that the study is looking at. It helps control for the “cause” in cause-effect relationships. The validity of the experiment is dependent on how well the treatment was manipulated.

(Bhattacherjee, 2012)

Random Selection is the process of randomly drawing a sample from a population. This ensures that each person in the population has a positive chance of being selected. Related to external validity.

Random Assignment is the process of randomly assigning subjects to experimental or control groups. This is standard process for ensuring the treatment groups and the control group are equivalent to each other prior to administration of treatment. Related to internal validity.

(Bhattacherjee, 2012)