Scientific Method

1. Scientific Method 7thGrade

2. Vocabulary • Control • Hypothesis • Law • Scientific Method • Theory • Variable

3. Use Your Noodle! Write the following in your Science Notebook. Analyze: Your portable CD player stops working. How do you try to fix it? You have 3 Minutes!

4. Critical Thinking • Critical thinking is when you use skills to solve problems. • Separating important information from information that is not important is a skill. • Identifying the problem is also another skill.

5. Solving Problems • Scientists use critical-thinking skills to try to solve problems and answer questions. • Solving problems requires organization. • Scientific Method • This is the steps scientists use to solve a problem.

6. Revise Hypothesis Repeat many times Hypothesis supported Hypothesis not supported

7. How are scientific problems stated? • 1st step in solving a problem scientifically is to state the problem. • A vet noticed that 2 cats that are being boarded were scratching and had patches of skin with red sores. • They both were fine when they first arrived. • The technician identified this as a problem. • Now she must decide how to gather information about the problem. • How would you solve this problem?

8. How is scientific information gathered? • Scientists collect information through laboratory observations and experiments. • Information can be collected from fieldwork done outside the laboratory • How would you find out how a bird builds a nest?

9. Back to the cat problem….. • The vet gathers information by watching the cats closely. • She watches to see if the behavior of the cats with the sores is different than the behavior of the other 2 cats. • She observes that other than the scratching, the behavior of the four cats is the same. • The vet finds out that the brand of cat food used at the clinic is the same as the one the cats get at home. • She decides that the two cats are reacting to something in their environment. • She notices that they seem to scratch most after using their litter boxes

10. How do scientists form a hypothesis? • After a scientist collect the information, they form a hypothesis. • A hypothesis is a prediction that can be tested. • After collecting the information, the vet hypothesizes that something in the cat litter is irritating the cats’ skin.

11. Use Your Noodle! Write the following in your Science Notebook. Define: What is a hypothesis? Give two examples. You have 3 Minutes!

12. How do scientists test a hypothesis? • Scientists test a hypothesis by performing an experiment. • In an experiment, they hypothesis is tested using controlled conditions. • Back to the cat problem…….

13. Cat Problem • The vet gets permission from the owner to test her hypothesis by running an experiment. • The vet reads the label on 2 brands of cat litter. • She finds that the ingredients of each brand are the same except that one has a deodorant. • The cat litter in the clinic has a deodorant. • The vet finds out that the litter the cats have at home does not have a deodorant.

14. Use Your Noodle! Apply: Do A Beriberi Interesting Case worksheet You have 5 Minutes!

15. How do scientists use control in an experiment? • The vet separates the cats with sores from the other 2 cats. • She puts each of the cats with sores in a cage by itself. • One cat is called the experimental cat. • This cat gets a litter box with litter that does not have deodorant • The other cat gets a litter box that has cat litter with deodorant. • The cat with the deodorant cat litter is the control

16. Control and variable • A control is the standard to which the outcome of a test is compared. • The control cat will be compared with the experimental cat at the end of the experiment. • Whether or not the cat litter has deodorant is the variable • A variable is something in an experiment that can change. • An experiment should have only one variable • Other than the difference in the cat litter, the vet treats the cats the same.

17. Use Your Noodle! Write the following in your Science Notebook. Analyze: Why is it important to have only one variable in an experiment? You have 3 Minutes!

18. How do scientists analyze data?Observation • During the week, the vet observes both cats. • She collects data on how often and when the cats scratch or chew. • She records the data in a journal • The data show that the control cat scratches more often than the experimental one does. • The sores on the experimental cat begin to heal. • The sores on the control cat do not.

19. How do scientists draw conclusions? • The vet draws the conclusion that the deodorant in the cat litter probably irritated the skin of the two cats. • To draw a conclusion is to get a logical answer to a question based on data and observation. • The next step is to accept or reject the hypothesis. • The vet accepts the hypothesis • If she had rejected it, then she world need to conduct new experiments.

20. Conclusion • The vet realizes that even though she accepted the hypothesis, she should continue her experiment to be surer of her results. • She should switch the cats to see if she gets the same results again. • However, if she did this, the healed cat might get new sores. • She makes an ethical decision and stops the experiment. • Ethical decisions are important in deciding what experiments should be done.

21. Use Your Noodle! Write the following in your Science Notebook. Draw Conclusions: If the hypothesis is rejected, the scientist has failed. Is this statement true or false? Explain your reasoning. You have 3 Minutes!

22. What do scientists do with results of experiments? • It is important to share the information when using scientific methods. • The vet shares her results with the cat’s owner • She tells him she has stopped using the cat litter with the deodorant. • One of the most important parts of the scientific method is communicating the results!

23. Developing Theories • After scientists report the results of an experiment that supports the hypothesis, many repeat the experiment. • If the results always support the hypothesis • The hypothesis can be called a theory. • Scientific Theory is an explanation of things or events based on scientific knowledge that is the result of many observations and experiments.

24. Theory Vs. Hypothesis • Hypothesis • An educated guess • Can be tested • Can be observed • Theory • Explains many hypotheses • Can raise new questions • Data or info from new experiments might change conclusions and theories can change

25. What is scientific law? • Scientific law is a statement about how things work in nature that seem to be true all the time. • Although laws can be modified as more information becomes known, they are less likely to change than theories.

26. Use Your Noodle! Write the following in your Science Notebook. Explain: Talk to your neighbor…. Give an example of a scientific law that has changed due to new information. You have 3 Minutes!

27. Laws • Laws tell you what will happen under certain conditions but do not necessarily explain why it happened. • For example: • You might learn about the law of heredity. • These laws explain how genes are inherited, but do not explain how genes work.

28. How do scientific methods help answer questions? • You can use scientific methods to answer all kinds of questions. • Using these methods does not guarantee that you will get an answer. • Often they lead to more questions and more experiments. • Science is about looking for the best answers to your questions.

29. Put it to the test. • Insert video

30. Use Your Noodle! Write the following in your Science Notebook. Explain: What scientific laws can tell you about nature. You have 3 Minutes!

31. Review Vocabulary • Put the following in your scientific notebook. • Define vocabulary from beginning of unit. • Draw a picture of each vocabulary term