The Scientific Method

1. The Scientific Method

2. What is the scientific method? A systematic approach to problem-solving.

3. Observations Hypothesis Experiments Theory Scientific Law

4. Vocabulary

5. Observations are facts you take in with your senses. They can be • Qualitative • Quantitative

6. Qualitative Observations • Use words to describe • the color, odor, shape, texture, or some other physical characteristic.

7. Quantitative Observations • Use numbers to describe a property. • Result from measurement. • Include a number and a unit. • Height, Mass, Temperature

8. What’s the difference between a fact and an inference? • Facts can be verified. They are objective. • Inferences are subjective. They involve conclusions drawn from data. • On Friday the 13th I saw a black cat. • On Friday the 13th I saw a spooky cat.

9. Hypothesis • Testable, educated guess to explain or predict an observation.

10. Experiments • An experiment is an organized process used to test a hypothesis. • Hold most variables constant. • Manipulate one variable. (Independent variable. Controlled by the scientist.) • Measure one variable. (Dependentvariable.)

11. Control • Control: Perform the experiment under specific conditions. • A standard for comparison • Compare the experiment with the control. They should differ by only one variable.

12. Conclusion • Judgment based on the experimental data. • Does the experiment confirm the hypothesis or does the hypothesis need to be modified?

13. Theory or Model • an overall explanation of some natural phenomenon. • Ex: Kinetic Theory • Supported by many experiments • Can be modified as necessary • Can be used to make predictions

14. Scientific Law • A relationship in nature that is supported by many experiments. • Law of Conservation of Energy • Newton’s Law of Gravitation

15. What’s the difference between a theory and a law again?

16. Attempt to explain why something happens. Summarizes what always happens. Theory vs. Law