Experimental Components 1 2 3 4 5 Experiment

Experimental Components 1

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Experiment to test hypothesis *overall question* Must include both experiments below Independent Variable Experiment. This experiment includes the thing that you are curious about, what you are testing. *At the end of this experiment you MEASURE the dependent variable which is the result. This experiment also includes Control Experiment. This experiment includes what you are comparing to. You either remove the independent variable or test what you have always done in the past. *At the end of this experiment you MEASURE the dependent variable which is the result. This experiment also includes Constants. Parts of the experiment that have to be kept the same for both experiments. 6

Let’s break it down………. 7

I have identified a problem with my tomato plants this past summer. They are growing very small tomatoes. I am curious, if I give them plant food will they grow larger tomatoes? 8

Identify variables, control and constants Independent variable- what is being tested is_______ (this is what the experimenter is deciding to test) Control- what you are comparing to is ________ Dependent variable- what you measure or the result is the _________ Constants- all other parts of your experiments that must be kept the same for both experiments. Some examples are __________________ 9

Identify variables, control and constants Independent variable- what is being tested is the plant food Control- what you are comparing to is no plant food Dependent variable- what you measure or the result is the weight of tomatoes Constants- all other parts of your experiments that must be the same for both experiments. Some examples are amount of sunlight, amount of water, type of tomato plant, and growth time 10

Independent Variable Experiment • 10 ml of plant food dissolved in water every week • Control Variable Experiment • Plant beefsteak tomato seeds • • Full sun for 8 hours a day • Use water from hose every day for 1 minute • Growing time 70 days 11

You would then measure the weight of the tomatoes (dependent variable) from both plants. You would compare the weight of the tomatoes from the plant that received plant food to the weight of tomatoes from plant that did not receive plant food. This data would help you form a conclusion whether plant food helps grow larger tomatoes. 12

Practice example- A teacher has the following question. She wonders if students use a calendar on their cell phones to record their homework will the percentage of homework turned in on time increase? She designs an experiment. What is the independent variable? What is the control? Name three constants in this experiment. 13