Variable- What could be changed. Only one will be changed in an experiment Independent variable - You (the experimenter) can change these. Dependent variable - What changes as a result of changes to independent variables. Control group - A group where you control all variables. Should have known results. Experimental group - A group where you change one variable. Difference from control group is assumed to be from the change of the variable. Example: Testing effect of sunlight on growing plants. Amount of sunlight received would be the independent variable, and would be different between the control group and experimental group. Amount of water received, type of soil, type of plant would be other independent variables, but should be the same between the two groups. Dependent variables would be things like root length, plant height, number of leaves grown, mass gained... ways to measure the growth of the plant.