define dependent variable in terms of science
1 Water. 2  Ruler. 3  Independent Variable-The independent variable is the thing that you change in the experiment. 4  All the other things in your experiment should stay the same. 5  For example, in our experiment the independent variable is the type of fertilizer. We'll use the same kind of pot, soil, and plant. We'll have the plants get the same amount of light and stay in the same room at the same temperature. We'll add the same amount of water. The only thing that will change is the kind of fertilizer. Dependent Variable-The dependent variable is the thing that changes because of the independent variable. For us, that would be the height of the plant.