1. Methods of Science

2. Science is used to investigate a natural occurrence.

3. Steps included when doing science Problem/Question Observation/Research Formulate a Hypothesis Design Experiment Run Experiment Collect and Analyze Results Conclusion Communicate the Results

4. Problem/Question 1. Problem/Question: Develop a question or problem that can be solved through experimentation.

5. Observation/Research 2. Observation/Research: Make observations and research about your topic of interest.

6. Observations 1. Are gathered through your senses 2. Are when a scientist notices something in their natural world

7. Observations An example of an observation might be noticing that many salamanders near a pond have curved, not straight, tails

8. Formulate a Hypothesis 3. Formulate a Hypothesis: Predict a possible answer to the problem or question. Example: If soil temperatures rise, then plant growth will increase.

9. Hypothesis Is a suggested solution to the problem. Is a suggested solution to the problem. Must be testable Must be testable Sometimes written as If…Then… statements Sometimes written as If…Then… statements Predicts an outcome Predicts an outcome

10. Hypothesis An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live. An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.

11. Experiment 4. Experiment: Develop and follow a procedure to test your hypothesis. A good experiment will includes several parts:

12. Parts of an Experiment Variables – factor that affects how an experiment works. There can be many variables in an experiment. Ideally only one variable is changed at a time in a good experiment. There can be many variables in an experiment. Ideally only one variable is changed at a time in a good experiment.

13. Types of Variables Independent Variable Dependent Variable Constants

14. Types of Variables Independent Variable (aka : manipulated variable, experimental variable) is the factor that is changed in an experiment. Only have one Independent variable at a time

15. Types of Variables Dependent Variable (aka : Responding variable) Is the factor that is measured or observed in an experiment This is what we collect data on.

16. Types of Variables Constants Are the other factors in an experiment that we keep the same (constant) so that they will not effect the outcome. Are the other factors in an experiment that we keep the same (constant) so that they will not effect the outcome. Controls and constants are not being tested. Controls and constants are not being tested. Used to make the experiment fair/valid. Used to make the experiment fair/valid.

17. Example of Controls & Variables For example, suppose you want to figure out the fastest route to walk home from school. You will try several different routes and time how long it takes you to get home by each one. Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

18. What are the Variables in Your Experiment? Varying the route is the independent variable Varying the route is the independent variable The time it takes is the dependent variable The time it takes is the dependent variable Keeping the same walker throughout makes the walker a constant. Keeping the same walker throughout makes the walker a constant.

19. One more thing… it is best to make several trials with each independent variable.

20. To be a Valid Experiment: You need two more parts Two groups are required for any valid experiment: Control Group : is the group in an experiment or study that does not receive treatment or testing Used for comparison

21. To be a Valid Experiment: You need two more parts Two groups are required for any valid experiment: Experimental Group a group of subjects who are exposed to the Independent variable and are being tested.

22. Collect and Analyze Results 5. Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs.

23. Data Results of the experiment May be quantitative (numbers) or qualitative

24. Data Must be organized Can be organized into charts, tables, or graphs

25. Conclusion 6. Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study and possible improvements to the procedure.

26. Conclusion The answer to the hypothesis based on the data obtained from the experiment

27. Communicate the Results 7. Communicate the Results: Be prepared to present the project to an audience. Expect questions from the audience.

28. Retest In order to verify the results, experiments must be retested.

29. Let’s put our knowledge of the Scientific Method to a realistic example that includes some of the terms you’ll be needing to use and understand. Review

30. Problem/Question John watches his grandmother bake bread. He ask his grandmother what makes the bread rise. She explains that yeast releases a gas as it feeds on sugar.

31. Problem/Question John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

32. Caution! Be careful how you use effect and affect. Effect is usually a noun and affect, a verb. “ The effect of sugar amounts on the rising of bread.” “How does sugar affect the rising of bread?”

33. Observation/Research John researches the areas of baking and fermentation and tries to come up with a way to test his question. He keeps all of his information on this topic in a journal.

34. John talks with his teacher and she gives him a Experimental Design Diagram to help him set up his investigation.

35. Formulate a Hypothesis After talking with his teacher and conducting further research, he comes up with a hypothesis. “If more sugar is added, then the bread will rise higher.”

36. Hypothesis The hypothesis is an educated guess about the relationship between the independent and dependent variables. Note: These variables will be defined in the next few slides.

37. Do you know the difference between the independent and dependent variables?

38. Independent Variable The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter. John is going to use 25g., 50g., 100g., 250g., 500g. of sugar in his experiment.

39. Dependent Variable The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable. In this case, it would be the size of the loaf of bread.

40. Experiment His teacher helps him come up with a procedure and list of needed materials. She discusses with John how to determine the control group.

41. Control Group In a scientific experiment, the control is the group that serves as the standard of comparison. The control group may be a “no treatment" or an “experimenter selected” group.

42. Control Group The control group is exposed to the same conditions as the experimental group, except for the variable being tested. All experiments should have a control group.

43. Control Group Because his grandmother always used 50g. of sugar in her recipe, John is going to use that amount in his control group.

44. Constants John’s teacher reminds him to keep all other factors the same so that any observed changes in the bread can be attributed to the variation in the amount of sugar.

45. Constants The constants in an experiment are all the factors that the experimenter attempts to keep the same.

46. Can you think of some constants for this experiment?

47. Constants They might include: Other ingredients to the bread recipe, oven used, rise time, brand of ingredients, cooking time, type of pan used, air temperature and humidity where the bread was rising, oven temperature, age of the yeast…

48. Experiment John writes out his procedure for his experiment along with a materials list in his journal. He has both of these checked by his teacher where she checks for any safety concerns.

49. Trials Trials refer to replicate groups that are exposed to the same conditions in an experiment. John is going to test each sugar variable 3 times.

50. Collect and Analyze Results John comes up with a table he can use to record his data. John gets all his materials together and carries out his experiment.

51. Size of Baked Bread (LxWxH) cm 3 Amt. of Sugar (g.) 123Average Size (cm 3 ) 25768744761758 501296118812961260 10011881080 1116 250672576588612 500432504360432 Size of Bread Loaf (cm 3 ) Trials Control group

52. Collect and Analyze Results John examines his data and notices that his control worked the best in this experiment, but not significantly better than 100g. of sugar.

53. Conclusion John rejects his hypothesis, but decides to re-test using sugar amounts between 50g. and 100g.

54. Experiment Once again, John gathers his materials and carries out his experiment. Here are the results.

55. Can you tell which group did the best?

56. Size of Baked Bread (LxWxH) cm 3 Amt. of Sugar (g.) 123Average Size (cm 3 ) 501296144012961344 601404129614401380 701638 15601612 8014041296 1332 90108012009721084 Size of Bread Loaf (cm 3 ) Trials Control group

57. Conclusion John finds that 70g. of sugar produces the largest loaf. His hypothesis is accepted.

58. Communicate the Results John tells his grandmother about his findings and prepares to present his project in Science class.

59. Solving a Problem 1)Identify a Problem 2) State Observations about the problem 3) Form a Hypothesis about the problem (if…then…) 4) Design an Experiment to test the hypothesis 5) Collect Data 6) Form a Conclusion 7) Retest