Presentation on theme: "Identifying Variables"— Presentation transcript:
1Identifying Variables Scientific MethodIdentifying VariablesLet’s say you are testing different colored lights on the rate of bean seed germination. To rephrase this, your problem is to germinate some bean seeds under different colors of light.
2You are testing how color affects the rate of bean seed germination You are testing how color affects the rate of bean seed germination. In other words, you will germinate bean seeds under different colors of light to see which one works the best.
3So, if you are testing different colored lights on the germination of seeds, what is the one thing that you will change on purpose?That will be the independent variable.
4If you said that you will change the color of light, then you are correct. The color of light used is the independent variable.
5If you are testing different colored lights on the germination of bean seeds, what are you measuring?This will be the dependent variable.
6If you said that you will measure how long it takes the seeds to germinate, then good for you! That’s correct!
7If you are testing different colors of light on the rate of bean seed germination, what would be some things that should stay the same?These are called constants.
8The following are all constants in the experiment and should not be changed. If you stated any of these, you are right!type of seedenvironmenttype of soilamount of soilmethod of planting seedstype of containerdepth of seedamount of watertype of wateramount of light
9Finally, if you are testing different colors of lights on the germination of seeds, what is the control?The control involves doing the experiment without the independent variable.
10If you said that the control would be white light, then you are really thinking! Taking away different colors just leaves plain white light.
11You did it!Try one more on your own. Pretend you want to know how caffeine affects the heart rate of middle school students. What would be the independent and dependent variables, constants and control?