Which variable is kept constant to ensure a fair experiment?

In a scientific experiment, keeping certain variables constant is crucial to ensure that the test conditions are reliable and that the results reflect the effect of the experimental variable. The variable that is kept constant is known as the control variable.

Control variables are all the factors that are not the focus of the experiment but could potentially influence the outcome. By maintaining these variables at a constant level, researchers can isolate the effect of the independent variable on the dependent variable. For instance, if a scientist is studying the effect of light intensity on plant growth, they might keep the amount of water, soil type, and temperature constant so that any changes in plant growth can be attributed directly to the variation in light intensity.

This systematic control helps to eliminate bias and variability that could skew the data and leads to more accurate and credible results, making the findings of the experiment more robust. Thus, identifying and controlling these variables is a fundamental aspect of the scientific method.