1. Scientific Method

2. The Scientific Method
involves a series of steps that are used to investigate a natural occurrence.
There is no single scientific method, but scientists tend to follow common steps.

3. The Scientific Method involves the following steps:
Problem/Question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion

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

5. Observation/Research
Make observations and research your topic of interest.
Observations are gathered through our senses throughout the natural world.

6. Observation/Research
From observations you make an inference.
An observation is made with your senses.
An inference is made when you apply prior knowledge to the observation.

7. Hypothesis Predict a possible solution to the problem or question.
Must be testable.
Sometimes written as an “If.... Then....” statement.
Predicts an outcome.

8. Hypothesis An example of a hypothesis might be:
“If soil temperatures rise, then plant growth will increase.”

9. Experiment Develop and follow a procedure to test the hypothesis.
The outcome must be measurable.

10. Experiment
An experiment to prove a hypothesis must contain the following parts:
experimental group - receives some form of treatment
control group - receives no experimental treatment
variable – factor in the experiment that is being tested.

11. Scientific Experiments Must Follow Rules
An experimenter changes only one variable and observes and measures what happens before changing the variable.

12. Remember: To be a Valid Experiment:
Two groups are required - the control and the experimental groups.
There should be only one variable.

13. The Control Variable
The experimenter makes a special effort to keep other factors constant so that they will not affect the outcome.
Those factors are called control variables.

14. What is the Purpose of a Control?
Controls are NOT being tested.
Controls are used for COMPARISON - to see the effect of the variable.

15. Variable Types
The factor that is changed is known as the independent variable.
The factor that is measured or observed is called the dependent variable.

16. 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.

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

18. Collect & Analyze Results
That information that is collected is called data.
There are 2 types:
Quantitative data =expressed as numbers
Qualitative data =descriptive but not numbers

19. Data/Results Must be organized.
Can be organized into charts, tables, or graphs.
Modify the procedure if needed.
Confirm results by retesting.

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

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

22. Retest
When scientists complete their experiment, the results must be retested to confirm the results.

23. After the Experiment
When scientists complete their experiment, the results must be repeated by other scientists before they can be accepted.

24. I Hate Everything About Crazy Teachers
1) Identify a Problem (through observation & research)
2) Form a Hypothesis about the problem
3) Design an Experiment to test the hypothesis
4) Analyze Data
5) Form a Conclusion
6) Test & test again!

25. Graphing the Data

26. Independent Variable The variable that is changed.
Independent variables must be controlled in an experiment except
the one being tested.
Graphed on X axis

27. Dependent Variable The variable that is being measured.
Graphed on the Y axis

28. Scientific Theory & Law
When the hypothesis has been supported by many different scientists over a long period of it becomes a theory.
Theory is a well-supported explanation.
A scientific law is a well-supported theory.