1. The Scientific Method

2. The Scientific Method involves a series of steps that are used to investigate a natural occurrence.
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3. We shall take a closer look at these steps and the terminology you will need to understand.

4. Observation/Research Formulate a Hypothesis Experiment
Scientific Method
Problem/Question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion
Communicate the Results

5. Steps of the Scientific Method
1. Problem/Question: Develop a question or problem that can be solved through experimentation.

6. Steps of the Scientific Method
2. Observation/Research: Make observations and research your topic of interest.

7. Steps of the Scientific Method
3. Formulate a Hypothesis: Predict a possible answer to the problem or question with an attempt at a reason.

8. Use the If….Then….Because format
Example: If I use brand X gasoline then I will get better mileage because it burns cleaner and thus releases more energy.

9. Steps of the Scientific Method
4. Experiment: Develop and follow a procedure.
Include a detailed materials list.
The outcome must be measurable (quantifiable).

10. Steps of the Scientific Method
5. Collect and Analyze Results: Modify the procedure if needed.
Confirm the results by retesting.
Include tables, graphs, and photographs.

11. Steps of the Scientific Method
6. Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study. Analyze any sources of error and suggest possible improvements to the procedure

12. Steps of the Scientific Method
7. Communicate the Results:
Good science publishes results so that peer review can occur.

13. An example of the scientific method.

14. Problem/Question
I have noticed that plants seem to grow better in the presence of sunlight. I wonder if sunlight is necessary for plant growth.

15. Observation/Research
I research the areas of sunlight and plant growth and try to come up with a way to test this question.

16. Formulate a Hypothesis
After conducting further research, I come up with a hypothesis.
“If I increase the amount of sunlight that my plants receive they should grow taller because light is necessary for photosynthesis.

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

18. Manipulated Variable
The manipulated (independent) variable is a factor that’s intentionally varied by the experimenter.
I am going to use 0% light, 50% light and 100% light in this experiment.

19. In this case, it would be the height of the plants.
Responding Variable
The responding (dependent) variable is the factor that may change as a result of changes made in the independent variable.
In this case, it would be the height of the plants.

20. Experiment I come up with a procedure and list of needed materials.
I then determine the control group.

21. 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.

22. 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.

23. My control group will be the plants grown in darkness
(0% light).

24. Controlled variables
Remember that I must keep all other factors the same so that any observed changes in the plants can be attributed to the variation in the amount of light. These other factors are called the CONTROLLED VARIABLES

25. Controlled variables
All of the other variables in an experiment that could change, but are held constant for consistency.

26. Can you think of some controlled variables for this experiment?

27. Controlled variables
They might include: type of soil, type of plant, fertilizer, wavelength of light, amount of water etc.

28. Experiment
Next I must write out the procedure for this experiment along with a materials list.
Next I should do several trials of my experiment and I should use as many plants as possible.

29. You should have at least 3 trials (preferably more)
Trials refer to replicate groups that are exposed to the same conditions in an experiment.
In other words I need to REPEAT MY EXPERIMENT TO VERIFY MY RESULTS.
Trials
You should have at least 3 trials (preferably more)

30. Collect and Analyze Results
I will then create a data table so I can record this data.
I get together all my materials and carry out this experiment.

31. Height of plants exposed to different amounts of light
Average Height of Plants (cm) Trials
Amt. of sunlight % 1 2 3
Average
Height (cm) 12 8 14
11.3 50 15 19 16
100 22 27
22.7
Control group

32. Collect and Analyze Results
I determine that there is definitely a relationship between the amount of sunlight and the height of the plants.

33. Collect and Analyze Results
Often times a graph is useful to analyze numerical results

34. Scientific Method Graphing: Must have units Title all graphs
Done in pencil
Use legend when necessary
Use the whole page
Responding Variable
Manipulated Variable

35. Experiment
Remember that I will carry out my experiment several times to validate my results and I will always try to use as many subjects (plants) as possible.

36. Validity & Reliability
Validity = Did the treatment cause the effect? Does the study follow proper scientific method?
Reliability = can you get the same (or similar) results if you repeat the experiment? Can others get the same results?

37. If I do all these things then I can safely say that I have carried out a good controlled experiment.