1. Scientific Method

2. Steps in the Scientific Method
Observation
Hypothesis
Experiment
Results (collect data)
Conclusion
Retest

3. Gathered through your senses
Observations
Gathered through your senses
A scientist notices something in their natural world that leads to a question.

4. Observations
An example of an observation might be noticing that many salamanders near a pond dark spots on their tails

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

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

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

8. Variable – factor in the experiment that is being tested

9. Experiment
A good or “valid” experiment will only have ONE tested independent variable!

10. Controls and Variables

11. Scientific Experiments Follow Rules
An experimenter changes one factor and observes or measures what happens.

12. The Control Variable
The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome.

13. What is the Purpose of a Control?
The Control is NOT being tested
The Control is used for COMPARISON

14. Other Variables
The factor that is changed by the experimenter is known as the independent variable.
The factor that is being measured or is unknown is called the dependent variable.

15. Example of Controls & Variables
For example, suppose you want to figure out if there is a faster route to walk home from school.
You will try several different routes beside your regular one and time how long it takes you to get home by each one.
Since you are only interested in finding a route that is faster for you, you will do the walking yourself.

16. What are the Variables in Your Experiment?
Varying the route is the independent variable
The time it takes is the dependent variable
The control is the regular route.

17. One more thing… it is best to make several trials with each independent variable.

18. Remember: To be a Valid Experiment:
Two groups are required --- the control & experimental groups
There should be only one variable tested at a time

19. Data Results of the experiment
May be quantitative (numbers) or qualitative (written observations)

20. Data Must be shared with others.
Can be organized into charts, tables, or graphs

21. Conclusion
Agrees or disagrees with the hypothesis based on the data obtained from the experiment

22. Retest
Change the hypothesis or in order to verify the results, retest the experiment.

23. Review

24. 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