1. Comprehensive Science II Mrs. Paola González
The Scientific Method
Comprehensive Science II
Mrs. Paola González

2. Scientific Method
What is the scientific method? It is a process that is used to find answers to questions about the world around us.
Is there only one “scientific method”? No, there are several versions with different number of steps. They all begin with the identification of a problem or a question to be answered based on observations of the world around us and provide an organized method for conducting and analyzing an experiment.

3. The Process

4. 1st Step
Problem/Question: Develop a question or problem that can be solved through experimentation.
Think about the difference between the two questions below:
Why has my CD player stopped working? (Can be answered by making observations)
What kind of music should I listen to on my CD player? (Depends on a personal opinion, not proper for experimentation)

5. 2nd Step
Observation and Research: Make observations and research your topic of interest, then we can infer and propose a possible answer.

6. 3rd Step
Formulate a Hypothesis: Predict a possible answer to the problem or question. Scientist must be able to carry out investigations to test it and either “support” or “fail to support” the hypothesis. (Always try to figure out the relationship between the independent and the dependent variables).

7. 4th Step Experiment: Develop and follow a procedure.
Include a detailed materials list.
All the factors that can change in an experiment are called variables.

8. Variables
Controlled variables: These are the factors that are kept the same throughout your experiments. Are also called constants. A controlled experiment is one in which only one variable is manipulated at a time.
Control is the group that serves as the standard of comparison.
Independent variable: The one variable that you purposely change and test. Also called manipulated variable.
Dependent variable: The measure of change observed because of the independent variable. Also called the respondent variable. It is important to decide how you are going to measure the change.

9. 5th Step
Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs.
Data Tables and Graphs are the facts, figures, and other evidence gathered through observations. They provide you with an organized way to collect and record your observations.

10. 6th Step
Conclusion: It is a brief summary here of what you discovered based on the results of your experiments. You need to indicate whether or not the data supports the hypothesis and explain why or why not. Make recommendations for further study and possible improvements to the procedure.

11. 7th Step
Communicate the Results: is the sharing of ideas and experimental findings with others through writing and speaking .Be prepared to present the project to an audience and expect questions from the audience.

12. Example
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.

13. The Problem …
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. John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

14. Observation and 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 and finally came up with and idea to set up his investigation.

15. Formulate 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.”

16. 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.

17. 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.

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

19. Control Group
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. 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.

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

21. Can you think of other variables?
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.

22. Other variables…
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…

23. Repetition and Replication
Repetition refers to multiple trials which refer to groups that are exposed to the same conditions in an experiment.
Replication is done by others.
John is going to test each sugar variable 3 times. John comes up with a table he can use to record his data.
John gets all his materials together and carries out his experiment.

24. Size of Baked Bread Loaf (cm3) L x W x H
Trials
Amt. of Sugar (g.) 1 2 3
Avg. Size (cm3) 25
768
744
761
758 50
1296
1188
1260
100
1080
1116
250
672
576
588
612
500
432
504
360

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

26. Repetition
John rejects his hypothesis, but decides to re-test (repeat) using sugar amounts between 50g. and 100g

27. Size of Baked Bread Loaf (cm3) L x W x H
Trials
Amt. of Sugar (g.) 1 2 3
Avg. Size(cm3) 50
1296
1440
1344 60
1404
1380 70
1638
1560
1612 80
1332 90
1080
1200
972
1084

28. Communication
John finds that 70g. of sugar produces the largest loaf. His hypothesis is accepted. John tells his grandmother about his findings and prepares to present his project in Science class.

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

30. Class Activities Brain Pop “The Scientific Method”
How stuff works video.
Define Vocabulary Words:
Scientific Method, Hypothesis, Variables, Independent Variable, Dependent Variable, Controlled Experiment, Constant, Control, Replication, Observation, Experiment.

31. Vocabulary Words
Scientific Method (Scientific Inquiry): Refers to the diverse ways in which scientists study the natural world and propose explanations based on the evidence they gather.
Hypothesis: It is a possible explanation for a set of observations or answer to a scientific question.
Variables: An event, condition or factor that can be changed or controlled in order to study or test a hypothesis in an experiment.

32. Vocabulary Words
Independent Variable: The one variable that is purposely changed to test a hypothesis. It is also called the manipulated variable.
Dependent Variable: The factor that change in response to the manipulated variable. It is also called the responding variable.
Controlled Experiment: An experiment in which only one variable is manipulated at a time.

33. Vocabulary Words
Constant: Something that does not change or is prevented from changing.
Control: The control is a particular sample that is treated the same as the rest of the samples except that it is not exposed to the manipulated variable.
Replication: In scientific research , the repetition of an experiment to confirm findings or to ensure accuracy.

34. Vocabulary Words
Observation: A statement based on what one has noticed or observed.
Experiment: A procedure that is carried out and repeated under controlled conditions in order to discover , demonstrate, or test a hypothesis; includes all components of the scientific method.

35. Class Activities Create a Scientific Method Foldable.
Sponge Bob Control and Variable Worksheet 1.
Sponge Bob Control and Variable Worksheet 2.
HOMEWORK: Study Vocabulary Words for quiz.