1. Scientific Methods Section 2.1
Objectives:
List and describe the steps of the experimental method.
Describe how scientists study subjects in which experiments are not possible.

2. Experimental Method (aka, “Scientific Method”)
Observation
Question
Hypothesis
Experiment
Only allow one variable to change
Use a control group for comparison
Repeat the experiment
Organize and analyze data
Communicate results

3. Correlation Method
What scientists use when they cannot answer a question experimentally.
What was Earth’s climate like 60 million years ago?
Does smoking cause lung cancer?
Correlation – reliable associations between two or more events
Tree rings
Lost Colony (Roanoke Island, VA)
Jamestown, VA

4. Rainfall and Tree Ring Width
Chapter 2
Section 1 Scientific Methods
Rainfall and Tree Ring Width

5. Good Scientists Are: Curious Skeptical Open to new ideas
Intellectually honest
Imaginative and creative (John Snow’s spot map)

6. John Snow’s Cholera Spot Map
Chapter 2
Section 1 Scientific Methods
John Snow’s Cholera Spot Map

7. Quick Quiz Why should the results of an experiment be repeatable?
Why are experiments designed to have as few variables – preferably only one – as possible?
Why is the correlation method a useful accompaniment to the experimental method?