Critical Appraisal of a Quantitative Research Article

Quantitative Research Sample Paper

Quantitative research entails collecting and analyzing data in the form of numbers. In this form of research, identification of the independent and dependent variable is key in making inferences after the data is interpreted.

Comparison of Independent Variables, Dependent Variables, And Extraneous Variables

In research, variables are used in delivering or studying the phenomena in the research topic. Dependent variables are the main concern in the research and is often the focus of the researcher during the study (Nieświadomy & Bailey, 2018). Additionally, the changes that happen to the dependent variable are measured to give the conclusions of the research. Independent variables are those that affect the dependent variable. These variables are manipulated and the change they make to the dependent variable is studied and measured. 

A researcher can control the independent variable, which means that the dependent variable is determined by the independent variable. Extraneous variables, on the other hand, are not independent but can affect research if they are not controlled. The extraneous variable impacts on how the dependent variable relates to independent variables and therefore needs to be controlled (Daniel, 2019).

Two Ways That Researchers Attempt to Control Extraneous Variables

The extraneous variables affect the outcome of the research and therefore require extensive attention and control. One of the approaches to control the extraneous variable is randomization, which is mostly used in research involving large sample sizes. In this approach, treatment is done randomly to the experimental groups (Bloomfield, & Fisher, 2019). During the treatment, there is an assumption that the extraneous factors affect all the groups evenly.

Matching can also be used in controlling the effect of the extraneous variable (Daniel, 2019). In this approach, the extraneous variables such as age, gender, are equally distributed in all the groups involved in the research. The shortcoming associated with this approach is that it is hard to completely match the groups and also the matched characteristic may not have relevance to the dependent variable. 


  • Bloomfield, J., & Fisher, M. J. (2019). Quantitative research design. Journal of the Australasian Rehabilitation Nurses Association, 22(2), 27–30.
  • Daniel, K. M. (2019). Introduction to Quantitative Research. Understanding Nursing Research: First South Asia Edition, E-Book: Building an Evidence-Based Practice.  Elsevier Health Sciences.
  • Nieświadomy, R. M., & Bailey, C. (2018). Foundations of nursing research. Pearson