An independent variable is a factor that is manipulated or controlled in an experiment to observe its effect on the dependent variable. It is the presumed cause in a cause-and-effect relationship.
Dependent Variable: The outcome or response measured to see if it is influenced by changes in the independent variable.
Control Variable: A factor that is kept constant to prevent it from influencing the outcome of an experiment.
Random Assignment: The process of assigning subjects to different treatment groups using randomization to eliminate bias.