1. Scientific Method

2. What is it? Why? A series of steps that are used to investigate a
natural occurrence.
Why?
Scientific understanding is always changing.
Life-long learners
New tools and techniques contribute to new discoveries.
Scientific understanding is always changing.
Life-long learners
Being open minded.

3. Steps of Scientific Method
Problem/Question
Observation/Research
Hypothesis
Predict a possible answer to the problem/question.
Example: If soil temperatures rise, then plant growth will increase.
Develop a question or problem that can be solved through experimentation.
Make observation and research your topic of interest.

4. Steps of Scientific Method
Experiment
Data-Collect & Analyze
Conclusion
Publish
Modify the procedure if needed.
Confirm results by retesting.
Include tables, graphs, and photographs.
Include a statement that accepts or rejects the hypothesis.
Make recommendations for further study and possible improvements.
Develop and follow a procedure.
Outcome must be measurable. (Quantifiable)
Scientific Journals
Be prepared to present material to an audience.
Expect questions.

5. Let’s put our knowledge of the scientific method to a realistic example, using some of the terms you will need to use and understand.

6. Problem/Question
John watches his grandmother make bread. He asks her what makes the bread rise. She explains that yeast releases a gas as it eats the sugar.
John wonders if the amount of sugar used will affect the size of the loaf of bread?

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

8. Formulate a Hypothesis
This is John’s hypothesis…”If more sugar is added, then the bread will rise higher.”

9. Hypothesis
The Hypothesis is an educated guess about the relationship between the independent and dependent variables.

10. Variables Independent Variable Dependent Variable
AKA manipulated Variable
Intentionally varied by the experimenter.
Ex. John is going to use 25g, 50g, 100g, 250, and 500g of sugar in his experiment.
MIX
Manipulative/Independent Variable on X-axis.
Dependent Variable
AKA responding Variable
Measured by experimenter
Ex. In this case it would be the size of the loaf of bread.
DRY
Depending/Responding Variable on Y-axis
DRY MIX

12. Experiment
John’s teacher helps him come up with a procedure and a list of materials.
She then discusses with John how to determine a control group.

13. Control Group The group that serves as a standard for comparison.
Usually a group in which there is “no treatment.”
It is exposed to the same conditions as the experimental groups, except for the variable being tested.
ALL experiments have a control group!
Because his grandmother always uses 50g of sugar in her recipe, he is going to use that amount as his control group.

14. Constants
John’s teacher reminds him to keep all other factors the same so that any changes that happen can be attributed to the variation in the amount of sugar.
Constants are all the factors in the experiment that are kept the same.

15. Can you think of any constants for John’s experiment?!

16. They might include… The other ingredients in the recipe.
The oven used.
Rise time.
Brand of ingredients.
Cooking time.
Type of pan.
Air temperature and humidity in the location where the bread is left out to rise.
Oven temperature.
Age of yeast.
List 3 constants in your notes.

17. Trails Each group is replicated a specific number of times.
makes sure that the first results weren't just an accident.
John decides to test each sugar variable 3 times.

18. Thinking like a scientist…
Information gathered by observation is called data. There are 2 kinds of data…
Quantitative- expressed in numbers-counting or measuring.
Qualitative- descriptive data-characteristics that can’t be counted.

19. Collect and Analyze Data
Keep written record of observations (data)
John creates a table to record all of his data in.
What do you think that John observes?
Size of Bread Loaf (cm³)
Amt of sugar (g.) 1 2 3
Average (cm³) 25
768
744
761
758
50 (control)
1296
1188
1260
100
1080
1116
250
672
576
588
612
500
432
504
360

20. He observes that the control worked the best, but not significantly better than the 100g of sugar trails.
Scientists often find that their hypothesis was false.
In such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.
He rejects his hypothesis and decides to retry his experiment using sugar amounts between 50g. And 100g.

21. Size of Bread Loaf (cm³)
Results
Size of Bread Loaf (cm³)
Amt of sugar (g.) 1 2 3
Average (cm³)
50 (control)
1296
1440
1344 60
1404
1380 70
1638
1560
1612 80
1332 90
1080
1200
972
1084

22. Conclusion Publish/Share
Use evidence to determine whether the hypothesis is supported or refuted.
John finds that 70g of sugar produces the largest loaf of bread.
His hypothesis is accepted.
Publish/Share
This way they can be viewed and repeated by others. Other may want to refine the experiment to account for other factors.
John shares his findings with his grandmother.

23. Theory
No theory is considered absolute fact, even if it becomes the dominate view of the majority.