NRS 445 Compare independent variables, dependent variables, and extraneous variables
Variables are the core components of a study as they provide an area for the study to provide answers to. Variables show the characteristics of the sample that’s under study and that every researcher must rally around variables. Variables are measurable characteristics or properties of people or things that can take on different values. (California State University n. d) However, variable selection is a complex problem, and so despite considerable work in this area there remain important issues that existing methods do not fully address. (Wang, G., et al., 2020).
The independent variable is the antecedent while the dependent variable is the consequent. A dependent variable is the variable that is affected by the independent variable. (Kaur, S.P., 2013). Independent variables can stand on their own. For instance, age, sex, height. Dependent variables are defined as those the values of which are influenced by other variables. (Chittaranjan, A., 2021).
Extraneous variables are variables that may affect research outcomes but have not been adequately considered in the study. (Olayemi, J. A. O., 2017). These variables occur in most studies and are uncontrolled, usually affecting the study variables during measurement and data analysis. To better manage the extraneous variables the researcher must adopt certain strategies to control the variables such as randomization and matching.
During randomization, the variables are evenly distributed to the experimental or treatment group so that each group has equal characteristics. (Dissertation Canada, 2014).
Matching, however, helps researchers to pair evenly all the features of the variables to different groups. Different confounding variables like gender, age, income etc. could be distributed equally among the group. (Dissertation Canada, 2014).
For instance, in research to determine Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia, the study randomized the population using the settings and gathered data from102 sites in the United States and Puerto Rico among adults aged 50 years or older with hypertension but without diabetes or history of stroke. (Williamson, J. D., et al., 2019). This system helped to control the extraneous variables because each data was equally distributed among each setting where data was collected.
References
Chittaranjan, A., (2021). A Student’s Guide to the Classification and Operationalization of Variables in the Conceptualization and Design of a Clinical Study.
Saul, M., (2023). Extraneous Variables in Research: Types & Examples.
Williamson, J. D., Pajewski, N. M., Auchus, A. P., Bryan, R. N., Chelune, G., Cheung, A. K., … & Sprint Mind Investigators for the SPRINT Research Group. (2019). Effect of intensive vs standard blood pressure control on probable dementia: a randomized clinical trial. Jama, 321(6), 553-561.
