1. Scientific Method

2. Steps in the Scientific Method
Observation
Hypothesis
Experiment
Data Collection
Conclusion
Retest

3. Observations Background information
Gathered through your senses/researched
A scientist notices something in their natural world
Background information

4. Observations
An observation might be noticing that many salamanders near a particular pond have curved, tails
Research may include learning about salamanders and about the area where they live.

5. background information
Hypothesis
A suggested solution to the problem.
Must be testable
Sometimes written as If…Then… statements
Predicts an outcome
Based on
background information

6. Hypothesis
An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.

7. A procedure to test the hypothesis.
Experiment
A procedure to test the hypothesis.

8. Remember: To be a Valid Experiment:
Two groups are required --- the control & experimental groups
There should be only one variable changed at a time
Several trials with similar results should be done

9. Data Results of the experiment
May be quantitative (numbers) or qualitative
Must be organized
Can be organized into charts, tables, or graphs

10. Conclusion
The answer to the question based on the data obtained from the experiment
This will either support the hypothesis or cause the hypothesis to be rejected

11. Retest
In order to verify the results, experiments must be retested with similar results.

12. Solving a Problem 1)Identify a Problem
2) State Observations about the problem
3) Form a Hypothesis about the problem (if…then…)
4) Design an Experiment to test the hypothesis
5) Collect Data
6) Form a Conclusion
7) Retest

13. The Strange Case of BeriBeri
Scientific Method In Action
The Strange Case of BeriBeri
In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi. Symptoms of the disease included weakness and loss of appetite, victims often died of heart failure. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria.
One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched this interesting case; he found that polished rice lacked thiamine, a vitamin necessary for good health.

14. State the Problem What is the Hypothesis
Scientific Method In Action
Should the hypothesis be supported or rejected
What should the new Hypothesis be
State the Problem
What is the Hypothesis
In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi. Symptoms of the disease included weakness and loss of appetite, victims often died of heart failure. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria.
One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched this interesting case; he found that polished rice lacked thiamine, a vitamin necessary for good health.

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

16. The Control Variable
The experimenter makes a special effort to keep everything else constant
Those factors are called control variables.

17. What is the Purpose of a Control?
Controls are NOT being tested
Controls are used for COMPARISON

18. 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.

19. 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.

20. Remember: To be a Valid Experiment:
Two groups are required --- the control & experimental groups
There should be only one variable changed at a time
Several trials with similar results should be done