Compare independent variables, dependent variables, and extraneous variables. Describe two ways that researchers attempt to control extraneous variables. Support your answer with peer-reviewed articles.
A variable can be defined as an event, idea, object, time, feeling, or any other type of category that a researcher is trying to measure. The three main types of variables, include dependent, independent, and extraneous variables (Allen, 2017). Independent variables are not affected by any changes from other variables that a researcher tries to measure (Allen, 2017). For instance, a research participant’s age might be an independent variable. Other factors such as how much television they watch or how much they eat, and which school they go to will not affect their age. In most research studies, a researcher will investigate the effect an independent variable may have on other variables normally referred to as dependent variables (Allen, 2017).
On the other hand, a dependent variable is a variable that will depend on other factors. A dependent variable will be affected by any changes to the independent variable (Allen, 2017). For example, an exam performance might be a dependent variable because it can change depending on various factors such as the length of studying, how much they revised, how much they slept before taking the test, and how hungry they were when they were taking a test. When researchers are looking for relationships between different variables, they are trying to figure out what changes affect a dependent variable (Allen, 2017).
Finally, extraneous variables are defined as variables that could affect the results of a research study of an experiment that is not part of the independent variable. All the extraneous variables that can affect the dependent variables in a study or experiment must therefore be controlled. One way that researchers try to control extraneous variables is through random sampling. In experiments, researchers may also try to control the environment, such as lighting temperature or noise, to avoid extraneous situational variables (Allen, 2017).
- Allen, M. (2017). The sage encyclopedia of communication research methods (Vols. 1-4). Thousand Oaks, CA: SAGE Publications, Inc doi: 10.4135/9781483381411.