Definition
Independent Variable (IV) refers to the variable in an experiment that is deliberately manipulated by the researcher in order to observe its effect on the dependent variable, with the goal of determining a cause-and-effect relationship.
Example
In a study on the effectiveness of a reward system on classroom behavior, the independent variable would be the introduction of the reward system (e.g., students receive tokens for completing tasks). Researchers observe how the manipulation of this reward system influences the dependent variable (the students’ on-task behavior).