An independent variable is a factor in an experiment that is changed or controlled to test its effects on the dependent variable. It is the variable that researchers manipulate to observe how it influences other variables. For example, in a study examining how different amounts of sunlight affect plant growth, the amount of sunlight is the independent variable.
In scientific research, identifying the independent variable is crucial for establishing cause-and-effect relationships. By altering the independent variable, researchers can determine if it leads to changes in the dependent variable, such as the height of the plants in the previous example. This helps in drawing valid conclusions about the effects of different conditions.