Compare independent variables, dependent variables, and extraneous variables. Describe two ways that researchers attempt to control extraneous variables
Compare independent variables, dependent variables, and extraneous variables. Describe two ways that researchers attempt to control extraneous variables. Provide an example of how this is applied using a peer-reviewed, primary research article.
Initial discussion question posts should be a minimum of 200 words and include at least two references cited using APA format. Responses to peers or faculty should be 100-150 words and include one reference. Refer to “RN-BSN Discussion Question Rubric” and “RN-BSN Participation Rubric,” located in Class Resources, to understand the expectations for initial discussion question posts and participation posts, respectively.
Sample Expert Answer
When defining features that make up a study, one that comes to mind is a variable. A variable in research is any factor or condition that can change or vary. It is mostly manipulated by researchers, measured, or observed to understand its relationship with other variables, helping to test hypotheses or answer research questions (Andrade, 2021). There are different types of variables in research, the first being independent variables. Independent variables in research are variables that are intentionally manipulated or categorized to observe their effect on another variable.
It is considered the cause in a cause-and-effect relationship. Researchers alter this variable to assess its impact on the dependent variable, which is the outcome being measured (Andrade, 2021). An example of an independent variable in a study by Kopp et al. (2024), which focused on physical activity and mental health in school-aged children, was the level of physical activity. In this case, the varying level of physical activity was measured to determine the influence on the dependent variable.
The dependent variable, on the other hand, is an outcome variable, meaning that it is a variable that is measured to assess the effect of the independent variable; meaning that the measurement or changes of the dependent variable depend on changes in the independent variable. In the study mentioned, the dependent variable was the mental health outcomes of school-aged children, which were influenced by their physical activity levels. The last type of variables are the extraneous variables. These are outside factors that can influence the dependent variable but are not the focus of the study.
Extraneous variables can introduce unwanted variability, potentially affecting the results or making it difficult to draw clear conclusions (Andrade, 2021). Researchers aim to control or account for extraneous variables to ensure the findings are primarily due to the manipulation of the independent variable. In the study, potential extraneous variables could include factors like sleep patterns, diet, or social interactions, which might also influence mental health but were not the main focus.
One of the ways of dealing with extraneous variables is by randomization. By randomizing sample selection and distribution, the extraneous variables are equally spread across all groups, thus reducing bias (Cobzaru et al., 2022). Matching is another strategy that can be used to control extraneous variables. In matching, the researcher pairs or groups participants based on similar characteristics, for example, age or gender, to control for variables that might influence the dependent variable. Both methods help isolate the effects of the independent variable, minimizing the impact of outside factors on the study’s results.
References
Andrade, C. (2021). A student’s guide to the classification and operationalization of variables in the conceptualization and design of a clinical study: Part 1. Indian Journal of Psychological Medicine, 43(2), 177. https://doi.org/10.1177/0253717621994334
Cobzaru, R., Jiang, S., Ng, K., Finkelstein, S., Welsch, R., & Shahn, Z. (2022). State of the art causal inference in the presence of extraneous covariates: A simulation study. AMIA Annual Symposium Proceedings, 2021, 334. https://pmc.ncbi.nlm.nih.gov/articles/PMC8861734/
Kopp, P. M., Möhler, E., & Gröpel, P. (2024). Physical activity and mental health in school-aged children: A prospective two-wave study during the easing of the COVID-19 restrictions. Child and Adolescent Psychiatry and Mental Health, 18, 4. https://doi.org/10.1186/s13034-023-00695-8
Sample Peer Response
Hello Joan,
Thank you for providing a great overview of key research variables, independent, dependent, and extraneous, and strategies for controlling extraneous variables. To add to your points, the independent variable in most cases is manipulated by the researcher to assess its effect on the dependent variable, which is the outcome being measured (Andrade, 2021). Extraneous variables, which are unrelated to the research hypothesis but potentially influence the results, can potentially lead to misleading conclusions. I agree that matching and randomization are effective techniques for controlling confounding or extraneous variables. By matching participants or randomizing assignments, researchers can reduce bias and isolate the true effect of the independent variable on the dependent one.
Reference
Andrade, C. (2021). A student’s guide to the classification and operationalization of variables in the conceptualization and design of a clinical study: Part 1. Indian Journal of Psychological Medicine, 43(2), 177. https://doi.org/10.1177/0253717621994334
