write a response to this discussion post, use references for support

Meare Cups May 28 5:23pm | Last reply May 30 2:42pm Ex post facto analysis is a non-experimental research design that utilizes data that was naturally occurring before analysis of variables, and without manipulation of those variables by the researcher (Lammers & Badia, 2004). Also referred to as cause-and-effect or causal-comparative research, it takes a retrospective approach to determining relationships between variables, especially when ethics preclude true experimental conditions. Examples of ex post facto research are commonly found in the social sciences, especially anthropology and sociology (Silva, 2010). A number of assumptions are made in an ex post facto design. First, it is assumed that the comparison groups are equal in all other ways besides the previously experienced independent variable (Allen, 2017). It is also assumed that, because the data is pre-existing, the researcher had no opportunity to manipulate variables (Silva, 2010). Finally, it is assumed in ex post facto analysis that the independent variable caused the dependent variable response because it occurred first (Lammers & Badia, 2004). Strengths of ex post facto analysis exist in the data being naturally occurring. When the independent variable has already existed, it is difficult to build a rigorous experiment to test its effects on the dependent variable, making ex post facto analysis most appropriate. Likewise, when exposure to an independent variable through experimental design is unethical, as in the case of exposure to traumatic life events, ex post facto analysis can provide an opportunity to research phenomena of interest without traumatizing experiment participants (Silva, 2010). The weaknesses of ex post facto analysis open the research design to threats to internal and external validity. If proper care is not taken to explore the cause-and-effect relationships present in ex post facto analysis, researchers may expose themselves to the logical fallacy of post hoc, ergo propter hoc, assuming that one variable was the cause of another because it occurred first (Lammers & Badia, 2004). Another assumption of this form of research that could lead to threats to a study's validity is the belief that because groups have already been exposed to the phenomenon, their exposure is equal and no other confounding variables may cause differences in results (Allen, 2017). While true experimental design is preferable for eliciting valid and reliable data, ex post facto analysis is a viable option for researchers who are exploring a pre-existing phenomenon, or when exposure to a phenomenon would cause grievous harm to research subjects. Researchers utilizing this method of exploring cause and effect will need to guard against many threats to the validity of their work, but have the opportunity to complete research that would otherwise be unethical if utilizing a more standard experimental design. References Allen, M. (2017). Ex post facto designs. In The sage encyclopedia of communication research methods (Vol. 4, pp. 469-471). SAGE Publications, Inc. https://doi.org/10.4135/9781483381411.n172 Lammers, W. J. & Badia, P. (2004). Nonexperimental research designs: Correlational design, ex post facto design, naturalistic observation, and qualitative research. In Fundamentals of behavioral research. Wadsworth. https://uca.edu/psychology/fundamentals-of-behavioral-research-textbook/ Silva, C. (2010). Ex post facto study. In Encyclopedia of research design (Vol. 0, pp. 466-466). SAGE Publications, Inc., https://doi.org/10.4135/9781412961288.n145