Do you know what affects a research study the most? Yes, it is the research variables that have a huge impact on your research. To minimise their impact, sometimes, the researchers keep some of the variables constant and do not involve them in the study. Those variables that are kept constant during a research study are called control variables. Keeping these variables constant in the research study is important. Do you know why? Most probably not, because you are here to know their importance. Well, you have come to the right place.
In today’s post, we will define the control variables. Along with the definition, we will also discuss their importance in any research study. Before any other thing, let’s define these variables so that the base gets set.
What are the control variables in a research study?
The control variables are the variables that are kept constant or limited in a research study. These are sometimes the variables that are not of any interest if you look at the study’s aims. Therefore, it is better that you ignore them and keep them constant during the study. For example, you are researching a question, “Does caffeine improve memory call? “ When doing research on this question, you can keep the following variables constant:
- Type of memory test
- Effect of noise on the environment
- Age of the respondent
What is the importance of control variables in research?
After reading the information above, you now have got a good idea of control variables, and the example above must have strengthened your understanding a bit more. As mentioned earlier, these variables hold much importance in a research study. Hence, now it is time to show why doing so is important. A brief description of the points below explains this well:
1. Limit the influence of external variables
The first point that highlights the importance of control variables is that they limit the influence of external or confounding variables on the research study. As you have made them constant and do not involve them in the research study, they do not play a role in the study. In this way, the results obtained after the study also become more valid. In addition to this, they increase the internal validity of the research. Hence, they limit the impact of external and confounding variables on the study effectively.
2. Help establish the true relationship
Every kind of research is aimed at finding the relationships between dependent and independent variables. What if external variables affect that relationship? Obviously, if it happens, you cannot establish the true relationship between the study’s variables. It is where the control variables help you a lot in your research study. As they are kept constant, they help you establish the true relationship between your study variables.
How to control different extraneous variables in a research study?
By now, you know that control variables increase the internal validity of the research and help in establishing the true relationship between research variables. However, you still do not know how to control different extraneous variables that can impact your study. Hence, a brief description of the three methods used in this context is as follows:
1. Random assignment
The first method to control an extraneous variable is by using the random assignment method. This is particularly useful in experimental research studies which have multiple groups. In this method of controlling the variables, the research participants are randomly assigned to different conditions. This random assignment of the respondents balances the characteristics of a group. It means there are no systematic differences between the respondents.
2. Standardised procedures
Sometimes, as a researcher, you make different groups in a research study. To create those groups, you use some kinds of procedures. If you want to get rid of the control variables, you must use standardised procedures for each group. Do not use different procedures for different groups. To control variables, you must hold constant things constant in every group.
3. Statistical controls
The third method to control extraneous variables is based on the statistical method. In the statistical method, you control the variable by modeling that variable along with the independent and dependent variables. For example, when you use regression analysis to know the relationship between the independent and dependent variables, you can model the extraneous variables too.
Conclusion
Conclusively, control variables are such variables that you keep constant throughout the study. Controlling the extraneous variables helps you limit their effect on the research study’s results. Also, by doing this, you increase the internal validity of your research study. So, read all the methods described above to control them and act accordingly.
Author Bio:
Mark Taylor is a trained Content writer from London. He has completed his English Literature (Hons) from Glasgow University. Mark currently lives in the UK and works as a freelance academic writer, and provides Research Proposal Help. Mark is a huge fan of the writing of Charlotte Bronte and Charles Dickens. In his blog posts, he talks extensively about the various authors and their writing styles.