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
Information gathered by the “Scientific Method”

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: Why is there little ground vegetation in this forest?
2nd step: Create a hypothesis
If…then statement
Example: If there are tall trees blocking sunlight, then few plants will grow near the ground.

5. 3rd step: Design an Experiment
Experiments test the independent variable
Independent variable: factor altered
Two parts to an experiment
Control group: comparison group
Ex: patch of forest with the large trees
2) Experimental group: contains the independent variable
Ex: patch of land w/o canopy trees
Data collected is called the dependent variable
Ex: growth height of the plants

6. Here is a well designed setup

7. Control Group Experimental Group
8cm rain/month
8cm rain/month
6 hours sun/day
6 hours sun/day
Grazing animals
60⁰ temp
60⁰ temp
Grazing animals
Large canopy trees
Patch of open land
The experimental plants grew 1 meter taller. What most likely caused this change?

8. Here is a poorly designed setup

9. Unknown! Too many changed variables!
Control Group
Experimental Group
8cm rain/month
8cm rain/month
6 hours sun/day
4 hours sun/day
Grazing animals
60⁰ temp
80⁰ temp
Grazing animals
Large canopy trees
Patch of open land
The experimental plants grew 1 meter taller. What most likely caused this change?
Unknown! Too many changed variables!

10. 4th Step: Data Analysis
Collect data to either support/reject your hypothesis
Ex: Plants on the ground grew almost 1m taller w/o the canopy trees
No hypothesis is proven after 1 experiment

11. 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

12. Farmer Bob wants to test his 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 but adds no fertilizer. In section B, he waters his crops as usual and also adds his 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
Substance added to the crops
Growth of the crops

13. 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

14. 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

15. 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

16. 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

17. Kobe Kuiz
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?