Identifying Variables, Control and Experimental Groups

• Controlled by experimenter

• Can be changed or manipulated by the experimenter

• Not affected by dependent variable

• Ask questions

• What's different in the experiment?

• What's being tested?

• What's causing the effect?

Mario believed that fertilizer will make the plant grow faster, so he treated one plant with fertilizer and the other plant did not receive fertilizer.

• Responds to independent variable

• Is measured in an experiment or study

• Ask questions

• What is responding to the cause?

• What is being measured?

Joshua believed that fertilizer will make the plant grow faster, so he treated one plant with fertilizer and the other plant did not receive fertilizer.

• Does not change

• Stays the SAME

• For example: same height, same amount of water are constants

• Receives treatment or test material

• For example: One plant receives fertilizer

• Fertilizer is the test material, so this plant is the experimental group.

• Does not receive the treatment or test material

• For example: One plant does not receive fertilizer

• Not receiving the fertilizer makes this plant the control group