what is a controlled variable in an experiment

A controlled variable in an experiment is a variable that is held constant or limited in a research study. It is also known as a constant or control variable. The controlled variable is not part of an experiment, and it is not an independent or dependent variable. However, it is important because it can affect the experiments result. Control variables help ensure that the experiment results are fair, unskewed, and not caused by the experimental manipulation. In other words, control variables help you ensure that your results are solely caused by your experimental manipulation. Aside from the independent and dependent variables, all variables that can impact the results should be controlled. If relevant variables are not controlled, they may influence the results, and uncontrolled variables are alternative explanations for your results and affect the reliability of your arguments. To control variables, you can hold them constant at a fixed level using a protocol that you design and use for all participant sessions.