Scientific Method

1. Scientific Method

2. Objectives Identify the steps used in scientific methods. Explain why scientists use scientific methods. Explain how scientific knowledge can change. Explain how scientific methods are used to answer questions and solve problems. Formulate testable hypotheses. Use information in tables and graphs to analyze experimental results.

3. What Are Scientific Methods? Scientific methods are the ways in which scientists answer questions and solve problems. When scientists try to solve a mystery, they perform problem-solving procedures called scientific methods. As scientists look for answers, they often use the same steps. But there is more than one way to use the steps. Scientists may repeat some steps or do them in a different order. When you use methods like these, you are solving problems in a scientific way.

4. Steps of the Scientific Method Identify the Problem (ask a question) Research (make observations/gather information) Form a Hypothesis Test the Hypothesis Analyze Data/Results Draw a Conclusion Communicate Results Remember scientists may repeat some steps or do them in a different order.

5. Identify the Problem (ask a question) Asking a question helps focus the purpose of an investigation. Scientists often ask a question after making observations. An observation is any use of the senses to gather information. Observations should be accurately recorded so that scientists can use the information in future investigations.

6. Problem What is in this box?

7. Research (make observations/gather information) Early people relied on mythology to explain what they observed. They believed that mythological gods were responsible for creating storms, causing volcanoes to erupt, causing earthquakes, bringing the seasons, and making comets appear in the sky. Some early civilizations went so far as to record what they saw. They developed calendars that described natural recurring phenomena. Later, civilizations created instruments to measure with. As instruments became better, accuracy of observations improved. While observations were being made, people made inferences, or conclusions, to help explain things.

8. Research (make observations/gather information) Any information that you gather through your senses is an observation. Take a look around to find answers to your question. Look up information in reliable resources such as textbooks, encyclopedias, and magazines or a quality search on the Internet Remember observations lead to answers only when they are accurate and carefully recorded.

9. Form a Hypothesis Once you have asked a question and made observations, you are ready to form a hypothesis. A hypothesis is a possible explanation or answer to a question that is based on prior scientific research or observations that can be tested (educated guess). A statement of cause and effect that can be used to set up a test for a hypothesis is called a prediction. Make Predictions Before testing a hypothesis, scientists often make predictions about what they think will happen in an experiment or investigation.

10. Researching on the Web Use specific keywords, try a variety Use quotation marks; but not too much Usually the first 15-20 sites on a list are the most useful otherwise you need to revamp your search Sites ending in .edu, .org, and .gov are usually more reliable than .com and .net Organizations websites (NASA, USGS, etc) often contain sites for students

11. Evaluating Sources Determine when it was written (use the most recent verifiable data) Determine who wrote it Determine the authors purpose for writing it Determine who the original audience was If in doubt verify with other sources

12. Hypothesis A stapler

13. Test the Hypothesis After you form a hypothesis, you must test it. Testing helps you find out if your hypothesis is correct or not. A hypothesis must be tested for scientists to learn whether an idea can be supported scientifically. Scientists test hypothesis by gathering data.

14. Test the Hypothesis Data are any pieces of information acquired through observation or experimentation. Designing an Experiment Designing a good experiment requires planning and a consideration of all factors. Keep It Under Control A controlled experiment may be used to test a hypothesis. A controlled experiment tests only one factor (variable) at a time and consists of a control group and one or more experimental groups. By changing only the variable, scientists can see the results of just that one change. Collecting Data Scientists keep clear, accurate, honest records of their data so that other scientists can repeat the experiment and verify the results.

15. Test the Hypothesis Make a box with a stapler in it and compare it to the original

16. Experiments After you have decided how you will conduct an experiment, you can begin testing. During the experiment, you should observe what happens and carefully record your data in a table. When you are making and recording observations, be sure to include any unexpected results. Many discoveries have been made when experiments produced unexpected results.

17. Experiment Ground Rules Plan the experiment in ADVANCE For your results to be valid or reliable, your tests should be repeated many times to see whether you can confirm your original results. If something in an experiment only occurs once, you cannot base a scientific conclusion cannot be made. Also, the number of samples being tested should be large. Report ALL results even unexpected ones

18. Variables vs. Controls in Experiments Variables Changeable factors in an experiment Independent variable- the ONE factor changed by the experimenter for testing purposes Dependent variable- the factor being measured in the experiment. It changes BECAUSE of the independent variable. Constants Factors in an experiment that DO NOT change. Basically Everything Else Control Compare results

19. Analyze Data/Results After they finish their tests, scientists must analyze the results. Analyzing the results helps scientists explain and focus on the effect of the variable. Analyzing the results helps scientists construct reasonable explanations based on the evidence that has been collected. Once you have your data, you must analyze them to find out whether the results support your hypothesis.

20. Analyze Results Can it be a stapler?

21. Draw a Conclusion At the end of an investigation, you must draw a conclusion. Your conclusion can help you decide what you do next. Scientists must conclude if the results of their tests support the hypothesis. Proving that a hypothesis is not true can be as valuable as proving that it is true.

22. What Next? New Hypothesis Repeat Experiment Analyze Data Communicate Results

23. Communicate Results Science depends on sharing information. One of the most important steps in an investigation is to communicate your results accurately and honestly. After finishing an investigation, scientists communicate their results to share what they have learned. Sharing allows other scientists to repeat experiments to see if they get the same results. By sharing, scientists can compare hypotheses. Sometimes, new data lead scientists to change their hypotheses.

24. Changes in Science

25. Changes in Science

26. Summing up the Scientific Method Determine the problem What do you want to know? Research Look for information on the topic Make a hypothesis A hypothesis is an educated guess. I think this will happen BECAUSE� Test Your Hypothesis Design an experiment to check your ideas. Analyze the results Study the data to determine the results Draw Conclusions Create a theory based on the data. Communicate the Results Provide results for critical reviews from peers

27. Science All Around

28. Science All Around

29. Diagram of the Scientific Method

31. Diagram of the Scientific Method

32. Scientific Method Scenario

33. A Real-World Question Engineers are scientists who put scientific knowledge to practical human use. Engineers create technology. Technology is the application of science for practical purposes. Engineers Czarnowski and Triantafyllou studied the efficiency of boat propulsion systems. Efficiency compares the energy used to move an object (the boat) forward with the energy supplied by the machine (engine). The Importance of Boat Efficiency. Making boats more efficient would save fuel and money. Based on their observations, Czarnowski and Triantafyllou asked the question: How can boat propulsion systems be made more efficient?

34. Nature Provides a Possible Answer Czarnowski studied penguins swimming and formed the hypothesis: A propulsion system that mimics the way a penguin swims will be more efficient than a propulsion system that uses propellers.

35. Testing Proteus Czarnowski and Triantafyllou built a model penguin boat called Proteus to test their hypothesis. The engineers took Proteus into open water to collect data. Pieces of information acquired through observation or experimentation is called data.

36. Data from Proteus

37. The Proteus Conclusion Czarnowski and Triantafyllou found that the penguin propulsion system was more efficient than a propeller system. So, they concluded that their hypothesis was supported.

38. Communicating About Proteus Czarnowski and Triantafyllou published their results in academic papers. They also displayed their project and its results on the Internet.

39. Online Scenario The scientific method in action

40. Think Teenage Science List the steps of the scientific method on the left side of your paper Create a teenage problem that you could use the scientific method to solve and state how each step would be used

55. If the groups were not labeled, how could you tell which group was the control group? Why is it important to have a control group when doing an experiment?