Scientific Method and Inquiry

1. Scientific Method and Inquiry

2. Inquiry and Deduction • Natural Laws – the set of rules that are obeyed by every detail of everything that occurs in the universe. • Inquiry – a process of learning that starts with asking questions and proceeds by seeking the answers to the questions. • Deduce – To figure something out from known facts using logical thinking.

3. Ask a Question, then…

4. Truth Test • To be accepted a theory must pass 3 tests: • 1. The theory must be supported by enough evidence. • 2. There can be NO evidence that contradicts the theory. • 3. The theory must be unique.

5. Scientific Evidence • Feelings and emotions are not scientific evidence • Scientific evidence accurately describes what happens in the real world. (e.g. numbers, tables, graphs, words, pictures, sound recordings, drawings, etc.) • Evidence must be objective. • Objective describes evidence that documents only what actually happened as exactly as possible. • Evidence must be repeatable. • Repeatable describes evidence that can be seen independently by others if they repeat the same experiment or observation in the same way.

6. Communicating Scientific Evidence • Scientists use similar terms so it will be easier to communicate results to one another. • Example: The metric system is used so that measurements do not need to be converted.

7. Scientific Theories • Theory – A scientific explanation supported by a lot of evidence collected over a long period of time. • Scientific theories are human attempts to describe natural law. • Theories are tested against evidence. • Current theory explains the new evidence. OR • Current theory DOES NOT explain the new evidence.

8. Hypotheses • Hypothesis – a possible explanation that can be tested by comparison with scientific evidence. Early hypotheses are rarely correct and are often modified as new evidence becomes available. • The word hypothesis is used to describe a possible explanation for a scientific mystery. • Must be testable to be scientific.

9. Scientific Method

10. Scientific Method • A theory is continually tested, if one piece of evidence does not agree with a theory, scientists must come up with a new hypothesis.

11. Other inquiry vocabulary • Independent variable/Manipulated variable – The one variable that is purposely changed to test the hypothesis. (x-axis) • Dependent variable/Responding variable – The factor that may change in response to the independent variable. (y-axis) • Control – A part of an experiment that does not experience the independent variable.

12. Writing a Formalized Hypothesis • Informal hypotheses: • Chocolate may cause pimples • Salt in soil may affect plant growth. • Formalized hypotheses: • If chocolate consumption and pimple frequency are related, then increased chocolate consumption will result in a greater amount of pimples. • If soil salinity and plant growth are related, then when a soil’s salt content is high a plant’s growth rate will increase.

13. Writing a Formalized Hypothesis • If chocolate consumption and pimple frequency are related, then increased chocolate consumption will result in a greater amount of pimples. • If, then statement… does not necessarily make a hypothesis. Sometimes they can be simple predictions or conclusions • In a formalized hypothesis, a tentative relationship is stated.

14. Writing a Formalized Hypothesis • Always contain the independent and dependent variables. • Benefits: clearly identifies what should be tested. A strong hypothesis will help you write a strong procedure. Also, it will enable you to be more focused when analyzing your results.