What is the independent variable in an experiment?

In an experiment, the independent variable is the factor that is manipulated or changed by the researcher to observe its effects on the dependent variable. It is the variable that is intentionally varied to determine how it influences the outcome of the experiment. For instance, if a scientist is testing different amounts of fertilizer on plant growth, the amount of fertilizer used is the independent variable, as it is the factor being altered to see how it affects the plants' growth (the dependent variable).

The independent variable is crucial because it allows researchers to establish cause-and-effect relationships. By controlling and changing this variable, scientists can assess its impact on other variables, thereby gaining insights into the dynamics of the system being studied.