SOME DEFINITIONS of Variables and Control(s)

• Manipulated Variable (also called the independent variable) - What you change on purpose in the course of your procedure.

• Responding Variable (also called the dependent variable) - What you do not change directly, but rather changes by itself in response to changes in the manipulated variable during the course of your procedure.

• Controls: - The factors you keep constant or hold fixed. A control is held fixed so that it doesn’t affect the outcome of the experiment.
• Students must only change one variable at a time, conduct repeated trials, and note their results.
• If they change more than one variable at a time, they will not know what affects their results.

EXAMPLES OF VARIABLES

• Manipulated Variable (Independent Variable): price (Brand) of paper towel
• Responding Variable (Dependent Variable): amount of water that is absorbed
• Control(s): size of paper towel amount of water poured on each towel temperature of the water used container in which towels are placed method of pouring