1. Steps of
the
Scientific Method

2. The Scientific Method is a process that is used to find answers to questions about the world around us.

3. Is there only one “scientific method”?
No, there are several versions.
Some have more/fewer steps but they all begin with problem or question and provide an organized method of conducting the experiment.

4. Scientific Method
1. Problem/Question
2. Research
3. State the Hypothesis
4. Design an Experiment
5. Conduct Experiment and Record Data
6. Analyze Data/Results
7. Conclusion
8. Communicate the Results

5. Steps of the Scientific Method
1. Problem/Question: Identify a testable question (tests one variable at a time) that can be investigated.

6. Steps of the Scientific Method
2. Research: Research information about the topic.

7. Do you remember the next step?

8. Steps of the Scientific Method
3. State the Hypothesis: State the hypothesis as a predicted answer to the question, what may be the possible outcome of the investigation
Example: If soil temperatures rise, then plant growth will increase.

9. Steps of the Scientific Method
Design an experiment: To test the hypothesis, controlling all variables except the independent variable
Plan for independent and dependent variables with repeated trials
Plan for factors that should be held constant (controlled variables) and/or plan for a control setup
List the materials needed to conduct the experiment
List the procedures to be followed
Plan for recording, organizing and analyzing data

10. Steps of the Scientific Method
Design an experiment: An investigation may involve a sample, or a portion of the total number, as a type of estimation.
The sample is used to take a representative portion of the objects or population for research.
A poorly chosen sample size can be unrepresentative of the whole.
Careful observations made from a proper sample size or manipulating variables within that sample size result in information and conclusions that might apply to the whole population.

11. Steps of the Scientific Method
5. Conduct Experiment and Collect Data: tables, graphs, or charts
Data- includes both scientific observations and inferences.

12. A scientific observation is gained by carefully identifying and describing properties using the five senses or scientific tools and can be classified as quantitative or qualitative.
Quantitative observations are observations that use numbers (amounts) or measurements(including the unit label) or observations that make relative comparisons, such as more than, all, less than, few, or none.
Qualitative observations are observations that are made using only the senses and refer to specific properties.

13. An inference is an explanation or interpretation of an observation based on prior experiences or supported by observations made in the investigation.
They are not final explanations of the observation.
There may be several logical inferences for a given observation.
There is no way to be sure which inference best explains the observation without further investigation.

14. Steps of the Scientific Method
5. Conduct Experiment and Collect Data:
Trials-
number of times the experiment is repeated.
repeated trials is needed for validity

15. Steps of the Scientific Method
5. Conduct Experiment and Collect Data:
Ex. Observation or Inference?
Grape juice causes stains on white fabric.
The height of a plant is 21.3 cm.
The temperature of the water in the pond is 17⁰ C.
Heat speeds up chemical reactions.

16. Steps of the Scientific Method
5. Conduct Experiment and Collect Data:
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.
(placebo group)

17. Steps of the Scientific Method
5. Conduct Experiment and Collect Data:
Constant-
Objects in the experiment that are the same for both the experimental and the control group.

18. Steps of the Scientific Method
5. Conduct Experiment and Collect Data:
Sample- portion of the total number
Representative portion of the objects or population of research
Poorly chosen sample size can be unrepresentative causing the experiment to not be valid

19. Steps of the Scientific Method
6. Analyze the Data: in the tables, graphs, or charts to figure out what the data means (describe the relationship between the variables)

20. Steps of the Scientific Method
7. Conclusion or Modification: Compare the results to the hypothesis and write a conclusion that will support or not support the hypothesis based on the recorded data

21. A valid conclusion can then be written and should include:
The relationship between the independent variable and dependent variables based on the recorded data, and
Whether the hypothesis was supported or not supported.

22. Steps of the Scientific Method
8. Communicate the Results: Be prepared to present the project to an audience.
Expect questions from the audience.

23. Think you can name all eight steps?
Conduct Experiment and Record Data
Communicate Results
Conclusion
Design the Experiment
State a Hypothesis
Research
Problem/Question
Analyze Data

24. After it’s all over…
Questions that can help decide what further investigations may be:
Can the procedure or product be improved?
What would happen if another independent variable were tested?
What are you wondering now?

25. 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.

26. She explains that yeast releases a gas as it feeds on sugar.
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.

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

28. 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?”

29. 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.

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

32. “If more sugar is added, then the bread will rise higher.”
State the 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.”

33. Note: These variables will be defined in the next few slides.
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.

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

35. 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.

36. In this case, it would be the size of the loaf of bread.
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.

37. She discusses with John how to determine the control group.
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.

38. 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.

39. All experiments should have a 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.

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

41. 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.

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

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

44. Constants -Other ingredients to the bread recipe, They might include:
-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…

45. 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.

46. John is going to test each sugar variable 3 times.
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.

47. 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.

48. Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of Sugar (g.) 1 2 3
Average
Size (cm3) 25
768
744
761
758 50
1296
1188
1260
100
1080
1116
250
672
576
588
612
500
432
504
360
Control group

49. 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.

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

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

52. Can you tell which group did the best?

53. Size of Baked Bread (LxWxH) cm3
Size of Bread Loaf (cm3)
Trials
Amt. of Sugar (g.) 1 2 3
Average
Size (cm3) 50
1296
1440
1344 60
1404
1380 70
1638
1560
1612 80
1332 90
1080
1200
972
1084
Control group

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

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

56. Observe your
world and come
up with a question
to answer using the
Scientific Method!