What is the purpose of a control variable in an experiment?

• A. To measure the dependent variable
• B. To manipulate the independent variable
• C. To validate the experimental conditions
• D. To randomly assign participants

Answer: (C)

The purpose of a control variable in an experiment is to validate the experimental conditions. Control variables are elements that are kept constant or unchanged throughout the experiment to ensure that any observed effects on the dependent variable can be attributed solely to the manipulation of the independent variable. By maintaining these constants, researchers can isolate the effects of the independent variable and make valid conclusions about the relationship between the variables being studied.

Keeping certain variables controlled helps prevent outside factors from influencing the results, thereby ensuring the experiment's reliability and repeatability. This is crucial for drawing accurate conclusions and understanding the true effects of the independent variable on the dependent variable. In essence, control variables help establish a baseline against which changes can be measured accurately.