What are the advantages and disadvantages in the use of a po

What are the advantages and disadvantages in the use of a posttest-only control group design versus a pretest-posttest control group design?

Solution

Pretest-Posttest Designs: There are many real world experimental designs, in which pretest-posttest designs are used for comparing groups of participants and measure the degree of change occurring as a result of treatments or interventions given to the participants.

Some example are: 1. education, here researchers want to know the effect of a new teaching method upon diffrent groups of children. 2. Evaluating the effects of counseling on patients, 3. reseachers wants to know effect of medical treatments etc. The only condition for this test is that all the subjects must be randomly assigned to groups, in a true experimental design.

The Posttest Only Design:

Experimental designs Pretest-posttest design is expanded form of the posttest only design with nonequivalent groups. This is known as the one of the simplest experiments used for testing the effect of an intervention or treatment.

These designs have two groups: one group is given the treatment and second known as the control group receives no treatment. Both groups undergoes exactly under the same tests.

Then researchers analyze that if the intervention or treatment had a significant effect. Example: Researcher want to test the effect of medicine: one group is given a medicine, and the control group is given none, and then reseacher analyze that if the drug really works.