1. Chapter 2
The Scientific Method

2. develop or revise hypothesis
The Scientific Method
STEP 5
testing
more collection of new and different evidence
STEP 4
theory
attempt to describe a natural law
STEP 3
testing
through observation and experiments
STEP 2
continually tested
develop or revise hypothesis
STEP 1
observation
hypotheses are then tested against evidence
of nature

3. The Scientific Method The scientific method is based on evidence
Scientific evidence is:
objective - the evidence describes exactly what happened and is free from bias or opinion
repeatable - others get the same results looking at the evidence the same way

4. The Scientific Method Hypothesis: a testable explanation or prediction
Theory: a human attempt to describe a natural law; supported by lots of evidence
- Theories explain how or why
Law: a theory that has been tested many times, by many different people, without any contradictions
- Laws state scientific facts

5. Hypotheses, Theories, and Laws
hypothesis
May become theory if supported by evidence from repeated exp.
May be supported by evidence, but is not a theory or law
May be tested, validated, and result in stating a natural law
A theory does NOT become a law; it attempts to explain a law
A theory may be discarded or revised as new evidence is gathered
Is simply a testable prediction
Laws help scientists make more accurate predictions
Laws are refined through further experiments