Scientific Method

1. Scientific Method Preparing for the Science Fair

2. Testable Questions • Can be answered through hands-on investigations. • They are NOT opinion questions or questions that can be answered by doing research in a book or on the internet. • You must be able to measure the results in some way for it to be considered a testable question.

3. 3 types of testable questions • 1. The effect question • What is the effect of sunlight on the growth of plants? • 2. The how does affect question • How does the color of light affect the growth of plants? • 3. The Which/What and verb question • Which/what paper towel is most absorbent?

4. Let’s practice identifying testable questions… • What types of apples grow in Michigan? • Not a testable question. It can not be tested through an experiment. You can answer this question with research on the internet or in a book.

5. How does talking to a plant affect a plants height? • Testable question. It is a How Does Affect question.

6. Which pill design- tablet, caplet, or capsule- will dissolve faster? • Testable question. It is a Which/What verb question.

7. Which planet is the most interesting one to study? • Not a testable question. It is an opinion and can not be proved in an experiment.

8. How does stirring affect the rate that salt dissolves in water? • This is a testable question. It is a How Does affect question.

9. Writing a Hypothesis • A hypothesis is a special kind of prediction that forecasts (predicts) how changing one part of an experiment will affect the results. • It is NOT a guess. It is an informed and well-thought out prediction that requires background information. • You can also think of it as a cause-effect statement.

10. A hypothesis is best written in the “If ______________, then _____________.” format. • After the “if” is the part the scientist will change on purpose. After the “then” is the result of the change. • Q: How does the amount of daylight affect how many eggs laid by a chicken? • H: If the amount of daylight increases, then the chickens will lay more eggs.

11. Q: How does the amount of leaves on a tree affect how many birds will build nests in it? H: If a tree has more leaves in it, then birds will be more likely to build a nest in it.

12. Q: How does the acid level of a lake affect how many fish live there? H: If a lake has a higher level of acid in it, then fewer fish will live there.

13. Q: How does the acid level of a lake affect how many fish live there? H: If a lake has a higher level of acid in it, then fewer fish will live there.

14. Variables • Variables are conditions that could affect the outcome of an experiment. • Think about all of the different things that might affect how well a student does on a test. • -- their amount of sleep • – how long they studied • –if they’re feeling well • – how well they paid attention in class • All of those things are variables- they affect how well the student will perform.

15. What variables can affect the number of fish in a lake? • Temperature of the water • The quality of the water- pollutants? • What the lake is used for

16. Discuss with your table group. • What variables can affect the taste of soda?

17. There are 3 types of variables. • The independent variableis what you change on purpose in an experiment. Usually there is only one independent variable in an experiment. Ask yourself “What did I change?” • The dependent variableis what you measure in an experiment.Ask yourself “What do I observe?” • The controlled variable is the condition that remains the same in an experiment.Ask yourself “What did I keep the same?”

18. Q: How does the size of the faucet opening affect the amount of water that flows out of it?

19. Q: How does the temperature of water affect the rate that sugar dissolves?