Download - The Scientific Method. An organized way to solve a problem through experimentation & observation
The Scientific Method
The Scientific Method
An organized way to solve a problem through experimentation & observation.
Start with an Observation
• Example : Listerine seems to be a better mouthwash and it has more antiseptic ingredients
Form a hypothesis
• Make an educated testable guess based on your knowledge.
Example:
Hypothesis :
How will a high antiseptic mouthwash affect bacteria in comparison to other mouthwashes?
Design an Experiment
• Devise a way to test your hypothesis.
Create a
CONTROLLED
experiment.
• A controlled experiment MUST have 2 groups.
CONTROL GROUP: all conditions remain the same
EXPERIMENTAL GROUP: only the condition that you are testing for is changed
ONLY 1 condition is changed!
• Establish the variables for your experiment.
INDEPENDENT VARIABLE: the variable that is changed by the experimenter (X axis for graphing) DEPENDENT VARIABLE: the effect measured due to the change of the independent variable
(Y axis for graphing)
Mouthwash Experiment
Petri dishBacteria grown
from swab
Control Group -no mouthwash
Experimental Group
Listerine
Scope
Wal-Mart brand
Mouthwash Experiment
INDEPENDENT VARIABLE:
DEPENDENT VARIABLE:
Type of Mouthwash
Amount of bacteria killed
Get Results & Analyze Data• Run the experiment & record
the data
Area of Inhibition of bacteria growth
Area of Inhibition for Mouthwash Brands
Control Listerine Scope Wal-Mart
5 min 0 mm 3 mm 2 mm 1 mm
10 min 0 mm 4 mm 3 mm 3 mm
15 min 0 mm 6 mm 5 mm 4 mm
20 min 0 mm 8 mm 6 mm 4 mm
Draw Conclusions
• Determine from the data collected if the hypothesis was correct or incorrect
EX: Listerine did kill more bacteria than the other brands because it had more antiseptic ingredients.