Scientific Method

1. Scientific Method Science 8

2. What is the Scientific Method? • A series of steps taken to acquire new knowledge or correcting and improving previous knowledge • In order to be considered scientific knowledge the experiment must be repeatedly tested and proven true

3. Scientific Method Steps • Purpose/Question • Research • Hypothesis • Experimentation • Conclusion

4. 1. Purpose/Question • begins with an observation that piques curiosity or raises a question • 3 questions considered in the purpose: • What do you want to know? • Why do you want to know it? • How may it benefit the world? Example) • What causes the roots of a plant to grow downward and the stem to grow upward? • What brand of mouthwash kills the most germs? • What type of building material absorbs the most sound?

5. L I B R A R Y I N T E R N E T Experiments Researchers Interviews 2. Research • Research is conducted to see what information and experiments have already been done on a particular topic. • Reviewing similar studies: • gives you background on studies that have already been done • helps you determine the factors you need to look at • The research stage will narrow and focus the research area through a process of elimination

6. 2. Research L I B R A R Y I N T E R N E T Experiments Researchers Interviews • Questions answered during the research phase: • What equipment and materials are needed and where can they be found? • How much time is needed to do a thorough job? • Where is the best place to conduct the experiment?

7. 3. Hypothesis • A statement about what you predict will result from the study • “educated guess” • an hypothesis is stated as an "if … then" statement • Ex.) If the faucet is opened then it will increase the flow of water • Ex.) If leaf colour change is related to temperature, thenexposing plants to low temperatures will result in changes in leaf colour. • Ex.) If light brightness is increased, then size of tomatoes will increase.

8. 3. Hypothesis • Two items must be present in an hypothesis: • it is testable • an experiment could be set up to test the validity of the statement. • it is falsifiable • an experiment could be conducted that might reveal that an idea is not true.

9. 4. Experimentation • Experiment is set up to test a specific hypothesis and it must be controlled. • A controlled experiment includes a control groupand an experimental group. • Control groups - are not manipulated and allows the experimenter to compare tests so they can feel confident that results are not due to chance. • Experimental group - The group being treated, or manipulated for the experiment. This group is identical to the control group EXCEPT that it is manipulated. • Independent Variables - part of your experiment that you will test to answer your hypothesis • Dependent Variable – What results from changing the independent variable

10. 4. Experimentation • Example of experimental group, control group, independent variable and dependent variable: • Testing whether an increase in light brightness will result in increased size of tomatoes Experimental Group -increased brightness of light Control Group -tomatoes under same light brightness Independent Variable -brightness of light Dependent Variable -size of tomatoes

11. 5. Conclusion • Analyze data • Support or reject hypothesis • Experimental results overview • Include any errors that resulted during experimentation • Report Results • Make recommendations for further studies that will improve the outcome

12. Scientific Method - Summary