Course: Research Methods
A control variable in social research is a factor kept constant to test the impact of an independent variable on a dependent variable.
In research, we often want to understand the effect of one thing on another. We call the thing we’re changing the independent variable, and what we’re observing the dependent variable. The control variable, then, is a factor that we keep the same so that it doesn’t interfere with our results. If you’re baking cookies, the independent variable might be the amount of sugar you use, and the dependent variable could be how sweet they taste. The control variables could be all the other ingredients and the oven temperature – you want those to stay the same.
Control Variables in Criminal Justice Research
Let’s take a look at how control variables work in different social research fields. In criminal justice, imagine researchers studying if a new community program decreases juvenile crime rates (the dependent variable). The program itself, being present or not, is the independent variable.
These could be factors such as the size of the community, the community’s average income, or the local police force’s size. All these factors may influence crime rates, but researchers want to isolate the program’s effect. Therefore, these control variables are kept constant across studied communities, whether by choosing similar communities or by statistically controlling for these variables in their analyses.
Social Work Research
Next, let’s see how these variables work in social work. A social worker might want to know whether an intervention program improves children’s school performance (dependent variable) in a foster care setting. The intervention program is the independent variable.
Control variables here might include the child’s age, the school they attend, or the foster home’s location. After all, these factors could influence school performance. So, the social worker will try to keep these factors constant while studying the impact of the intervention program.
Political Science Research
Lastly, consider political science. A researcher might study if a new voting law influences voter turnout (dependent variable). The law, either in effect or not, is the independent variable.
Control variables in this research could be the state’s population size, the candidates running, or even the weather on election day! These could impact voter turnout but aren’t what the researcher is studying. Accordingly, they try to keep these variables constant or control for them statistically in their analysis.
Why Control Variables Matter
In conclusion, control variables are vital in social research. By keeping certain factors constant, researchers can better determine if the change in the independent variable indeed causes a change in the dependent variable. Without them, it would be difficult to determine whether the results are due to the independent variable or some other factor. They are, therefore, crucial for creating valid, reliable research. All things considered, understanding control variables can help us better comprehend and evaluate social research studies.