What Is an Independent Variable

An independent variable is a variable that doesnt depend on another variable and isnt changed by any factors an experimenter is trying to measure. Its the variable that is controlled or changed in a scientific experiment to test its effect on the dependent variable. The independent variable is denoted by the letter x in an experiment or graph. Independent Variable Example For example, a scientist is testing the effect of light and dark on the behavior of moths by turning a light on and off. The independent variable is the amount of light and the moths reaction is the dependent variable. For another example, say you are measuring whether amount of sleep affects test scores. The hours of sleep would be the independent variable while the test scores would be dependent variable.A change in the independent variable directly causes a change in the dependent variable. If you have a hypothesis written such that youre looking at whether x affects y, the x is always the independent variable and the y is the dependent variable. Graphing the Independent Variable If the dependent and independent variables are plotted on a graph, the x-axis would be the independent variable and the y-axis would be the dependent variable. You can remember this using the DRY MIX acronym, where DRY means dependent or responsive variable is on the y-axis, while MIX means the manipulated or independent variable is on the x-axis More About Variables The independent variable is only one of the variables in an experiment. Learn about other variables and how they are used to design an experiment. What Is a Variable in Science?What Is a Dependent Variable?What Is a Control Group?What Is an Experimental Group?