Identify the research design in the study that you will replicate by designing your proposal.
Non experimental study.

Summarize the definition of that design from the textbook.
In Non experimental/ Observational studies the researchers do not manipulate the variable. Some observational studies start with a presumed cause and then go forward to a presumed effect. The text uses an example of lung cancer studies and groups subjects into non-smokers and smokers. (Polit & Beck, 2014, p. 159).

List two threats to internal validity from any of the research reports that you are using for your proposal.
Selection threat: Due to the fact that nurses in different departments, positions and shifts might be effected differently by situations that lead to burnout.
History threat: We are looking at the causes of nurse burnout at the work place, other factors could be contributing to burnout such as family, social and/or financial stress that are unknown to the researcher.

List and summarize (from the textbook) two research designs that you never heard of prior to this course. A. Quasi-Experimental Design: The designs lack randomization which is the signature of a true experiment. For example they might separate groups by last name or seating assignment. (Polit & Beck, 2014). B. Cross-Sectional Design: These are done over a specific period of time which can range from minutes to years depending on the study. (Polit & Beck, 2014).
Describe how you might use those designs in a future study that you conduct.
The Quasi-Experimental control group research can be a quicker and less expensive study especially in an epidemiology emergency like the Coronavirus that has recently originated in China.
The Cross-sectional design would be helpful in a study that dealt with patients with lung disease and a history of vaping.
References:

Polit, D. F., & Beck, C. T. (2014). Essentials of nursing research: appraising evidence for nursing practice. Philadelphia: Wolters Kluwer.