Please respond with a paragraph to the following post, add citations and references.

The four most commonly used designs for research studies are descriptive, correlational, quasi-experimental, and experimental."(Grove, Gray & Burns, 2015). Descriptive and correlational designs can be referred to as non-experimental designs because the focus is on examining variables as they naturally occur in environments and not in the implementation of a treatment by the researcher.

Experimental research is when a researcher is able to manipulate the predictor variable and subjects to identify a cause-and-effect relationship. This typically requires the research to be conducted in a lab, with one group being placed in an experimental group, or the ones being manipulated, while the other is placed in a placebo group, or inert condition or non-manipulated group. A laboratory-based experiment gives a high level of control and reliability. .(Sousa, Driessnack & Menders, 2007).

Non-experimental research is the label given to a study when a researcher cannot control, manipulate or alter the predictor variable or subjects, but instead, relies on interpretation, observation or interactions to come to a conclusion. Typically, this means the non-experimental researcher must rely on correlations, surveys or case studies, and cannot demonstrate a true cause-and-effect relationship. Non-experimental research tends to have a high level of external validity, meaning it can be generalized to a larger population. .(Sousa, Driessnack & Menders, 2007).

References

Grove, S., Gray, J., & Burns, N. (2015). Understanding nursing research (6th ed.). St. Louise, MO: Elsevier Saunders.

Sousa, V. D., Driessnack, M., & Mendes, I. A. (2007, June). An overview of research designs relevant to nursing: Part 1: Quantitative research designs. Revista Latino-Americana de Enfermagem, 15(3). https://doi.org/10.1590/S0104-11692007000300022