In a short essay, list and discuss the three specific preexperimental designs

What will be an ideal response?

a. One-shot case study is a preexperimental design in which a single group of test units is exposed to a treatment X, and then a single measurement on the dependent variable is taken. This type of design is constructed using a nonrandom sampling process in which the subjects are self-selected or selected arbitrarily by the researcher. Without randomization, the observed dependent variables are subject to the influences of several extraneous variables.
b. One-group pretest-posttest design is a preexperimental design in which a group of test units is measured before and after exposure to the treatment. Although this design is considered better than a case study, the validity of conclusions is questionable since extraneous variables are largely uncontrolled due to lack of randomization and a control group.
c. Static group is a two-group experimental design in which one of the groups acts as a control group. Only one group, the experimental group, receives the experimental treatment. The subjects are not assigned randomly, and measurements are made on both groups following the treatment. The treatment effect would be measured as the difference between the control and experimental group.