1. Scientific Method

2. Steps in the Scientific Method
Observation
State the Problem
Hypothesis
Experiment
Data Collection (Results)
Conclusion
Retest

3. Observations Gathered through your senses
An INFERENCE is based on previous experience

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

5. Experiment A procedure to test the hypothesis.
Only test ONE factor per experiment!
Contains controls and variables

6. Controls and Variables
Control contains all factors in experiment that remain constant (the same)
Used for comparison to identify change
Variables can be:
Independent variable: the factor that is changed (goes in X-axis)
Dependent variable: the factor that you are measuring as a result of the change you caused (goes in Y-axis)

7. Example of Controls & Variables
For example, suppose you want to figure out the fastest route to walk home from school. (your independent variable)
You will try several different routes and time how long it takes (your dependent variable) 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 (control – you don’t change during the walk)

8. Remember: To be a Valid Experiment:
Two groups are required --- the control (containing the constant) & experimental groups (containing independent and dependent variables)
Only one factor being tested per experiment!
Your experiment should be repeated at least three times

9. Results
Contains data
May be quantitative (numbers) or qualitative (description)
Organized in charts, tables or graphs

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

11. Retest
In order to obtain reliable results, experiments must be retested.

12. Scientific Theory vs. Law:
Scientific Theory is the explanation of a natural phenomenon supported by many observations and experiments over time. Not a “hunch”.
Scientific Law explains phenomena that occur in certain conditions, as in math and physics, without explaining why.

13. Mythbusters’ are elephants afraid of mice
Scientific method demonstration