Evaluating Design Choice and Threats to Validity in a Essay

Evaluating Design Choice and Threats to Validity in a Quasi-Experimental Design - Essay Example The present author selected the choice of quasi experimental design with the rationale of avoiding the need to have two different sample sizes to work with because that would have been time consuming and defeated the overall time frame set for the researcher for the given academic research. With the quasi experimental design however, all that the researcher needed to do was to use a comparison group, without the need to employing the use of an experimental group: a situation that would have brought about the need for a posttest at the end of the given study (Cheng, 2009). The choice of quasi experimental design brought about two major types of validity, which were external validity and internal validity. With reference to external validity, it could be said that because quasi experimental designs deal with real-world scenarios, it is often easier to guarantee external validity because the results of the researcher are often evidently clear for public scrutiny. The absence of random sampling however inhibits the general internal validity of the quasi experimental design (Sanigorski et al., 2008). The author was therefore not in a better position to critically explain the validity that existed because the use of comparison groups defeated the idea of internal validity of the research. Sanigorski, A. M., Bell, A. C., Kremer, P. J., Cuttler, R., & Swinburn, B. A. (2008). Reducing unhealthy weight gain in children through community capacity-building: Results of a quasiexperimental intervention program, Be Active Eat Well. International Journal of Obesity, 32,