1. Intro to Scientific Inquiry 2

2. The Scientific Method*
Making observations
Asking questions
Developing a hypothesis
Designing an experiment
Collecting data
Making inferences
Results (peer review)

3. Experimental Design
*Experiment: def. – an investigation consisting of procedures that tests a hypothesis by collecting data under controlled conditions.
Investigation
Procedures
Controlled conditions

4. Control vs. Experimental Group
*Control: def – the standard in which all conditions in the experiment are kept the SAME
*Experimental (test) group: def – all conditions are kept the same except for the condition in question being tested
Why do we need both groups?

5. Flaming Dollar Revisited
Question: What is the effect of the amount of isopropyl alcohol on the dollar bill’s burning intensity?
What is the Control Group?
What is the Experimental Group?

6. Flaming Dollar Control Group
(Control: def – the standard in which all conditions in the experiment are kept the SAME)
Control group – soak the dollar bill in ONLY WATER. (NO ALCOHOL IN SOLUTION)

7. Flaming Dollar Experimental Group
(Experimental group: def – all conditions are kept the same except for the condition in question being tested)
Experimental group – soak the dollar bill in varying concentrations of isopropyl alcohol. (testing the effect of amount of alcohol)

8. Variables
*Independent variable: def – the one condition that is tested because it affects the outcome of the experiment
*Dependent variable: def – the observable condition that “depends” on changes made to the independent variable

9. Flaming Dollar Revisited
Question: What is the effect of the amount of isopropyl alcohol on the dollar bill’s burning intensity?
What is the Independent Variable?
What is the Dependent Variable?

10. Flaming Dollar Independent Variable
(Independent variable: def – the one condition that is tested because it affects the outcome of the experiment)
Independent variable – the amount (concentration) of alcohol used in solution to soak the dollar bill

11. Flaming Dollar Dependent Variable
(Dependent variable: def – the observable condition that “depends” on changes made to the independent variable)
Dependent variable – the burning intensity that depends on the different amounts of alcohol used.

12. FINAL THOUGHT! *ONLY TEST ONE variable at a time!!!
Example: Flaming Dollar
Amount of alcohol used
Different $ bill amounts used
MUST TEST SEPARATELY!!!