Scientific Method Vocab Review to make life easier!

Variables Variables used in an experiment or modeling can be divided into three types: Independent Variable Dependent Variable Controlled

Independent Variable The Independent Variable (IV) is something that causes a change in the experiment Example: How much water flows through a faucet at different openings? IV = Water faucet opening (closed, half open, fully open, etc.) Example: Does heating a cup of water allow it to dissolve more sugar? IV = Temperature of the water Example: Does fertilizer make a plant grow bigger? IV = Amount of fertilizer

Dependent Variable The Dependent Variable (DV) is the effect (or result) of the change in the experiment. This is what scientist measure in an experiment. Example: How much water flows through a faucet at different openings? DV = Amount of water flowing, measured in liters/min Example: Does heating a cup of water allow it to dissolve more sugar? DV = Amount of sugar that dissolves completely, measured in grams Example: Does fertilizer make a plant grow bigger? DV = Growth of the plant, measured by its height

Fair Experiments For an experiment to be considered a fair test there should only be ONE independent variable In other words, there should only be one cause for change/ one thing that could change the end result/effect A fair experiment: Does the temperature of water affect how much sugar can be dissolved? One cause = water temperature An unfair experiment: Does the temperature of water and amount of sugar affect how much sugar can be dissolved? Two causes = water temperature and sugar amount

Controlled A Controlled Variable is something you try to keep constant (the same) in the experiment. Example: How much water flows through a faucet at different openings? C = The faucet; water pressure Example: Does heating a cup of water allow it to dissolve more sugar? C = Stirring; type of sugar Example: Does fertilizer make a plant grow bigger? C = Same type of fertilizer; same size of pot for each plant; same type of plant in each pot; same type of soil for each plant; same amount of water and light…