Article Critique-Non-experimental Designs

Question 1 

There are different approaches to research among them quasi-experimental and correlational research designs. Notable differences exist between these two research designs. First, correlational design involves the measuring of two variables in which a researcher is interested in while making minimal efforts to gain control over the extraneous variables and seeking to evaluate the existing relationship between the variables ( Gravetter & Forzano, 2018) . On the other hand, a quasi-experimental design involves the researchers working to manipulate an independent variable without primarily assigning random participants to conditions. Additionally, it can be argued that quasi-experiments revolve around numerous groups with an independent variable in contrast to correlational experiment that has a single group with several independent variables. It can also be concluded that in quasi-experiments subjects can be randomized through controlling the group while in contrast, correlational design randomization is aimed at controlling the variables.

Question 2 

The research designs employed in the two studies have differing results in measuring the studies’ hypotheses. The study that is applying quasi-experiment sought to determine the effects of integrated care models for the aged on the satisfaction of informal caregivers with support and care services ( Jansen, Huijsman, & Fabbricoti, 2014) . Applying quasi-experimental design for this study can be viewed as inappropriate noting that the results that the research yielded may not be realistic. Furthermore, the research design has produced minimal evidence, which makes it challenging to make definitive conclusions regarding the study. It is worth mentioning that the insufficient evidence that has been drawn from the study is not consistent with the existing literature regarding the topic of study. Subsequently, employing a different research design say experimental design would yield better results.

On the other hand, the study employing correlational research design has the objective of evaluating the relationship that probiotics have on overall mental health ( Torres & Economou, 2016) . As the researchers have indicated, the research design did not fully support the primary hypotheses even though there were insightful findings regarding probiotics, exercise, physical, and mental health.

Question 3 

Drawing conclusions from non-experimental research designs can be limited due to numerous reasons. First, non-experimental models tend to be shallow thus limiting the extent to which researchers can utilize the existing literature regarding the study topic ( Gravetter & Forzano, 2018) . It should be noted that non-experimental designs are concise further limiting the allowance for post-treatment data gathering. Often, the failure to include applied treatments or experimentation in research studies makes studies to be one-dimensional where the focus is given to limited variables, thus making it challenging to draw meaningful conclusions. Additionally, non-experimental research designs often do not yield significant data amounts with which researchers can utilize to bring truly revealing or valuable findings.

Studies have proven that non-experimental designs prove challenging to show the correlation between the different variables that are being measured in the study ( Gravetter & Forzano, 2018) . Additionally, unlike in experimental studies, non-experimental designs do not provide researchers with the opportunity to alter the various variables within the study thus limiting the data that can be deduced making a weaker case for correlation.

Question 4 

Both studies have random samples which have been used in addition to having several problems that were identified during the study. One of the problems noted is the fact that the results that have been deduced from both studies have not been consistent with the existing literature due to the research designs used. Subsequently, the studies have lost external validity since their results cannot be generalized and are not reflective of the real world. When the studies lose external validity, the results achieved may not hold meaningful use.

References  

Gravetter, F. J., & Forzano, L. B. (2018).  Research Methods for the Behavioral Sciences . Boston, MA: Cengage Learning. 

Jansen, B., Huijsman, R., & Fabbricoti, S. N. (2014, March 29). A quasi-experimental study of the effects of integrated care intervention for the frail elderly on informal caregivers? Satisfaction with care and support. Retrieved from https://bmchealthservres.biomedcentral.com/articles/10.1186/1472-6963-14-140 

Torres, C., & Economou, P. J. (2016, March 30). Probiotics can Improve Mood: A Correlational Study Investigating the Relationship between Probiotics and Overall Mental Health. Retrieved from https://www.omicsonline.org/open-access/probiotics-can-improve-mood-a-correlational-study-investigating-therelationship-between-probiotics-and-overall-mental-health-2329-8901-1000143.php?aid=70478