The major difference between experimental and nonexperimental research designs is the manipulation of the independent variable(s). Three main points characterize experimental research, including (1) controlled manipulation of at least one independent variable; (2) a treatment group and a control group; and (3) random assignment of the participants to treatment or control group (Grove, Gray, & Burns, 2015). A common experimental research design used in studies in the healthcare field is the pretest-posttest design with treatment and control groups. An example of this would be to measure vital signs in premature newborns before the intervention, skin-to-skin contact, is applied and then measure them again during application of skin-to-skin contact, also known as Kangaroo care. This type of study would enable the researcher to evaluate if the independent variable, Kangaroo care, affects vital signs, dependent variables, of the premature babies. In experimental research, causality between independent and dependent variables is studied under highly controlled conditions which makes experimental research the “most powerful quantitative method” (Grove, Gray, & Burns, 2015, p.34). As previously stated, independent variable(s) are not controlled by the researcher in nonexperimental studies. Correlational research is an example of nonexperimental research design in which the researcher measures two variables with little to no control of extraneous variables and the relationship between these two variables is then analyzed (Price, Jhangiani, & Chiang, n.d.).
Experimental research design is a study used to test cause and effect amongst variables. There are two groups associated with this research. One is the experimental group and the other is the control group. The experimental group is given the controlled independent variable and the control group is not. The study measures the difference between the groups. This research can provide strong evidence and is appropriate when a researcher has detailed research. Example of an experimental group is some patients with Congestive Heart Failure getting discharged on a continuing care program and some CHF patients getting discharged without program. The study would seek to see if a continuing care program with decrease the occurrence of readmission.
In non-experimental designs the emphasis is on examining variables as they naturally occur in settings and not on the implementation of a treatment by the researcher. Some of these nonexperimental designs include a time component (Groves, Burns, and Grey. 2015). Example of a non-experimental design would be if employees would take part in share a ride program if there was incentive involved.
The experimental research design is based off investigator controlled manipulation. Non- experimental research design lacks the manipulation and is studied as they naturally occur in the setting.