Independent Variable: This is the variable that is manipulated or changed in an experiment to observe its effect on the dependent variable.

• Example: In a study on plant growth, the amount of sunlight each plant receives (e.g., 2 hours, 4 hours, 6 hours) is the independent variable.

Dependent Variable: This variable is measured or observed in response to changes in the independent variable. It depends on the independent variable.

• Example: In the same plant growth study, the height of the plants after a certain period is the dependent variable, as it depends on the amount of sunlight they received.

Controlled Variable: These are the variables that are kept constant throughout the experiment to ensure that the results are due to the independent variable alone.

• Example: In the plant growth experiment, controlled variables could include the type of plant, the soil type, water amount, and temperature, all of which should remain the same for all plants to ensure a fair test.