The Scientific Method

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. 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: IFListerine has more antiseptic ingredients than Crest or the Wal-Mart brand, THENit will kill more bacteria.

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

8. CONTROL GROUP: all conditions remain the SAME! It is a group you do not do anything to. • A controlled experiment MUSThave 2 groups. 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 Petri dish Bacteria grown from swab Listerine Experimental Group Crest Brand Wal-Mart brand

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

12. 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. 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

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