1. The Scientific
Method

2. What is Science?
Science: Process that produces information about nature
Steps: Observation & Experimentation
Why: Apply the results to the real world
Why: Better understand our world

3. Scientific Method
Defined: Series of steps to collect information or solve problems
1) Observation
2) Hypothesis
3) Experimentation
4) Data Analysis
5) Conclusion

4. Observation and Hypothesis
1st step: Make an observation
Example: I seem to sleep better when I play relaxing music.
2nd step: Create a hypothesis
If…then statement
Example: If there is relaxing music playing, then I will sleep longer.

5. 3rd step: Design an Experiment
Two parts to an experiment
Control group
Receives no special treatments
Used as comparison
2) Experimental Group
Same as control group, except…the independent variable
Independent variable = one factor that differs from the control group
Dependent variable: Data measured

6. Here is a well designed setup

7. Did the music cause the extra sleep?
Control Group
Experimental Group
Curtains closed
Curtains closed
Soft bed
Soft bed
Usual exercise
Healthy meals
Usual exercise
Healthy meals
No music while sleeping
Music while sleeping
Test for 1 month
Test for 1 month
Did the music cause the extra sleep?
Average 6.2 hours sleep
Yes. It was the only reason to explain the extra sleep.
Average 7.5 hours sleep

8. Control Group Experimental Group Average 6.2 hours sleep
Curtains closed
Curtains closed
Soft bed
Soft bed
Usual exercise
Healthy meals
Usual exercise
Healthy meals
No music while sleeping
Music while sleeping
Test for 1 month
Test for 1 month
30 seconds to discuss with your neighbor.
What’s the independent variable?
What’s the dependent variable?
Average 6.2 hours sleep
Average 7.5 hours sleep
Presence of music
Amount of sleep

9. Here is a poorly designed setup

10. Did the music cause the extra sleep?
Control Group
Experimental Group
Curtains closed
Soft bed
Soft bed
Curtains open
Increased exercise
Usual exercise
Healthy meals
Healthy meals
No music while sleeping
Music while sleeping
Test for 1 month
Test for 1 month
Did the music cause the extra sleep?
Average 6.2 hours sleep
Average 7.5 hours sleep
Unknown. Extra sleep could have been due to other variables.

11. A teacher wants to know if her new teaching method is more successful than traditional teaching methods. She compares test scores of her period 2 class (received the traditional teaching method) verses her period 4 class (received new teaching method). Each class has a random mix of honors students.
Period 2 students
Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________
Period 4 students
Teaching method
Test scores

12. A high school soccer team on average scores 2
A high school soccer team on average scores 2.2 goals per game by practicing 4 days a week. The coach wants to see if practicing 5 days a week will help the team score more goals. The coach has the team practice 5 days per week and compares the goals scored per game.
Practicing 4 days per week
Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________
Practicing 5 days per week
Length of practice
Goals scored per game

13. The city of Los Angeles wants to know if there is a connection between physical fitness and air pollution. Fifty volunteers from the mayor’s office agree to be tested. First, they are asked to ride a stationary bike for 1 hour in a pollution-free air chamber. A week later, the 50 volunteers return and are again asked to ride a stationary bike for 1 hour in a chamber filled with air pollutants common to Los Angeles. Their heart rates are monitored throughout the 1 hour bike rides.
Volunteers who breathed common polluted air
Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________
Volunteers who breathed clean air
Quality of air breathed
Heart rates

14. Farmer Bob wants to test a new fertilizer to help his crops grow better. He sections off two large areas of his field. In section A, he waters his crops as usual and uses his normal fertilizer. In section B, he waters his crops as usual and but adds the experimental fertilizer. After 1 growing season, he records the growth of the crops.
Section A
Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________
Section B
Type of fertilizer used
Growth of the crops

15. The United States military wants to see if soldiers with only 4 hours of sleep can operate at the same level as those who normally get 7 hours of sleep. One hundred solders are allowed to only sleep for 4 hours a night and another hundred are allowed to sleep for 7 hours a night. During the day, the soldiers are tested for marksmanship on the firing range. . . .
Soldiers with 7 hours sleep
Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________
Soldiers with 4 hours sleep
Amount of sleep given
Score on the firing range

16. 4th Step: Data Analysis
Without
music
With
music
Collect data to either support/reject your hypothesis
No hypothesis is proven after 1 experiment

17. 5th Step: Conclusion
Your findings could be shared and repeated by others
Theory develops over time
Theory = long standing hypothesis
Theories and hypotheses change based on new information

18. Recap
Place the 5 steps of the scientific method in order from start to finish.
Data analysis, Observation, Conclusion, Experimentation, Hypothesis
In which stage of the scientific method are graphs usually created?
In which stage of the scientific method are the two variables identified?
Which variable is the difference between the control and experimental group?
Which group of an experiment is used for comparison and contains no changes?
How many independent variables should exist in a well designed experiment?
What is the data collected from the independent variable called?
Vocabulary: Science, Scientific method, Hypothesis, Control group, Experimental group, Independent variable, Dependent variable, Theory