Extraneous Variable – Definition, Example

Extraneous Variable

Extraneous Variable


An extraneous variable is a factor that influences the dependent variable but is not part of the experiment.

An Extraneous variable is any variable in a research study that has the potential to impact the outcome of that study. These variables can be either internal or external to the research itself. Internal extraneous variables are those that are related to the research design or methodology, while external extraneous variables are those that are not under the control of the researcher.

Extraneous variables can often be difficult to identify and control for, which is why they can pose such a threat to the validity of a study. When designing a research study, it is important to take into account all potential extraneous variables and plan for how they will be controlled. Without proper controls in place, extraneous variables can easily lead to inaccurate or invalid results.

Example of Extraneous Variable

An Extraneous Variable would be: In a study investigating whether or not listening to classical music improves test scores, the extraneous variables would be anything that influences test scores but is not related to listening to classical music. This could include variables such as intelligence, study habits, or motivation. It is important to control for extraneous variables when conducting research because they can potentially produce invalid results.

When to use Extraneous Variable

There are times when extraneous variables can be useful. For example, if a researcher is interested in studying the effects of a new medication on anxiety levels, an extraneous variable such as age could be included in the analysis to control for its potential influence. This is important because anxiety levels tend to increase with age and therefore age could confound the results if it is not controlled for.

However, there are also times when including extraneous variables can be problematic. If a researcher conducts an experiment to determine the effects of a new medication on anxiety levels, it would be inappropriate to include age in the analysis because age is not an independent variable under study. The inclusion of extraneous variables introduces additional variance into the analysis and can skew results.

Purpose of Extraneous Variable

The purpose of an extraneous variable is to identify and control for variables that could potentially influence the results of an experiment.

Extraneous variables are important to consider in any experiment, as they can have a significant impact on the results. In some cases, extraneous variables can even invalidate an entire study. Therefore, it is critical to identify any extraneous variables and take steps to control for them.

Advantages of Extraneous Variable

Some Advantages of Extraneous Variable are:

  • Extraneous variables can provide insight that you didn’t expect or intend to find.
  • They can help add validity to your research by providing another factor that can be controlled or accounted for.
  • They can also serve as a way to replicate your findings in future studies

Limitations of Extraneous Variable

One limitation of extraneous variables is that they can confound the results of research. This means that it may be difficult to determine whether the observed effect is due to the independent variable or the extraneous variable. For example, imagine a study looking at the effect of a new reading intervention on student achievement. If students who receive the intervention also happen to have better teachers, it may be hard to tell if any observed improvement is due to the intervention or the quality of instruction.

About the author

Muhammad Hassan

I am Muhammad Hassan, a Researcher, Academic Writer, Web Developer, and Android App Developer. I have worked in various industries and have gained a wealth of knowledge and experience. In my spare time, I enjoy writing blog posts and articles on a variety of Academic topics. I also like to stay up-to-date with the latest trends in the IT industry to share my knowledge with others through my writing.