1. The Scientific Method

2. The Scientific Method
An organized way to solve a problem through experimentation & observation.

3. The 6 Steps of the Scientific Method

4. Example: Mouthwash kills bacteria. Which brand works best?
1. State the Problem
Form a question about a specific event
Example: Mouthwash kills bacteria. Which brand works best?

5. 2. Collect Information Research the problem Example:
Read the labels of types of mouthwash
Which has the most antiseptic (germ-killing) ingredients.

6. 3. Form a hypothesis
Make a testable educated prediction based on your research.
A hypothesis can be recognized by an “if, then” statement.
Example: IF Listerine has more antiseptic ingredients than Crest or the Wal-Mart brand, THEN it will kill more bacteria.

7. 4. Design an Experiment Create a way to test your hypothesis. Create a
CONTROLLED
experiment.

8. A controlled experiment MUST have 2 groups.
CONTROL GROUP: all conditions remain the SAME! It is a group you do not do anything to.
EXPERIMENTAL GROUP: a group or many groups who you test.
The experiment is performed on this group.

9. Establish the variables for your experiment.
INDEPENDENT VARIABLE: the variable that you change or manipulate (X axis for graphing)
DEPENDENT VARIABLE: the change or result that happens when the independent variable is used (Y axis for graphing)

10. Mouthwash Experiment Control Group -no mouthwash Experimental Group
Petri dish
Bacteria grown from swab
Listerine
Experimental Group
Crest Brand
Wal-Mart brand

11. Type of Mouthwash Mouthwash Experiment Amount of bacteria killed
INDEPENDENT VARIABLE:
Type of Mouthwash
DEPENDENT VARIABLE:
Amount of bacteria killed

12. Run the experiment & document the data
5. Collect & Analyze Data
Run the experiment & document the data

13. 2 Types of Data
QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart
QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

14. QUANITATIVE EX: Area of Inhibition for Mouthwash Brands
QUALITATIVE EX: The control group and the Wal-Mart brand have a strong smell; the Listerine & Scope don’t smell as bad.
QUANITATIVE EX: Area of Inhibition for Mouthwash Brands
Control
Listerine
Scope
Wal-Mart
5 min
0 mm
3 mm
2 mm
1 mm
10 min
4 mm
15 min
6 mm
5 mm
20 min
8 mm

15. 6. 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.

16. Scientific Method Vocabulary
Observation- the act of observing (touch, taste, smell, feel, see, etc.)
Inference- a quick conclusion that attempts to explain an observation
Prediction- to forecast; to guess the outcome of a situation beforehand
Analysis- to separate or break apart into smaller sections for study

17. Scientific Method Vocabulary
Conclusion- to close or bring to an end; to accept or reject a hypothesis in an experiment
Data- recorded observations or measurements
Hypothesis- a tentative explanation that accounts for a set of facts & that can be tested by further investigation

18. Scientific Method Vocabulary
Controlled Experiment- an experiment in which all variables except the ONE being tested are identical in order to make the experiment fair & the results reliable
Variable- any factor in an experiment that could affect the results & is therefore tested separately

19. Scientific Method Vocabulary
Controlled Variable- a variable that is not changed
Independent Variable – a variable that you purposely manipulate (manipulated variable)
Dependent Variable- the variable being observed that changes in response to the independent variable (responding variable)

20. Scientific Method Vocabulary
Quantitative Data- data that involves numbers or measurement usually in the form of a chart or graph
Qualitative Data- anecdotal or descriptive data that does NOT involve numbers or measurement