1. The Scientific Method Sect 1-3 Mr. McGee

2. a.Science attempts to know how and why things happen. b.Science can only work with ideas that are testable and measureable: c.Which of the following ideas cannot be scientifically tested and measured? a.Temperature of the body after 10 minutes of exercise. b.Happiness of the child when given 5 pieces of candy. c.Felt pain when given an increasing level of voltage. d.Loudness of a frogs croak at sunset over the course of a year. e.Water pressure after inserting lots and lots of salt. f.Average attitude of the ghost when summoned by a psychic. g.The effects of drinking increasing levels of Gatorade on arm strength.

3. a.Science attempts to know how and why things happen. b.Science can only work with ideas that are testable and measureable: c.Which of the following ideas cannot be scientifically tested and measured? a.Temperature of the body after 10 minutes of exercise. b.Happiness of the child when given 5 pieces of candy. c.Felt pain when given an increasing level of voltage. d.Loudness of a frogs croak at sunset over the course of a year. e.Water pressure after inserting lots and lots of salt. f.Average attitude of the ghost when summoned by a psychic. g.The effects of drinking increasing levels of Gatorade on arm strength.

4. The Scientific Method To solve questions asked in science, we use the Scientific Method.

5. Observations Hypothesis & Predictions Experiments Conclusions Publish Results for Peer Review Theory The Scientific Method

6. 1. Collect observations to help ask questions. i.What is the effect of sunlight on the rate of plant height growth? ii.How does the loudness of cicada’s noise change through the summer? iii.What is the effect of caffeine on heart rate? The Scientific Method

7. 2. Develop a testable hypothesis and make a prediction. i.Hypotheses is an “educated guess” about what you think is going to be the outcome of a test. ii.Predictions is the expected outcome of a test, if the hypothesis is correct. Should be phrased as an “If…, then…” statement. (Note, sometimes, your prediction may also be a hypothesis). i.Hypothesis: Caffeine will affect the heart by making the heart rate to increase in BPM. ii.Prediction: IF a person is exposed to increasing levels of caffeine... …THEN we will see an increase in heart rate BPM. The Scientific Method

8. 3. Conduct an experiment to test the hypothesis. i.Experiments are a set of procedures that can be replicated. ii.Control Group – The group that receives NO change. i.Person drinks decaffeinated soda. iii.Experimental Group – The group that alters ONE variable from the control group. i.Person drinks caffeinated soda. iv.Independent Variable [IV] – The factor that you change. i.Caffeine in the soda v.Dependent Variable [DV] – The outcome that is being measured. i.Heart rate The Scientific Method

9. 4. Draw conclusions based on the data from experiment. Recall the hypothesis: “Caffeine will affect the heart rate by making the heart rate increase in BPM.” Does the experiment confirm or falsify your hypothesis? One possible answer: “Yes… heart rate increased in BPM when people were exposed to caffeine in soda.” The Scientific Method

10. 5. Publish results for Peer-Review, so that others may see. Peer-review allows scientists all over the world to read and possible replicate your experiment. If you did everything right, they should also be getting the same results. The Scientific Method

11. 6. If experiment is repeated over and over, and other scientists confirm your results… it becomes a Theory. Remember: Theories may take YEARS to form and thousands of scientists to help confirm. The Scientific Method

12. Compare and Contrast: Hypothesis & Theory??? Latin Roots: Hypo = Less thanThesis = Statement Therefore… Hypothesis = Less than a statement, before experiment Theory= Full statement, after conclusions are made

13. Here’s an actual experiment…

14. Lets do some observations… Gasoline works by combustible vapors igniting within the engine… The better the vapor in gasoline, the better the mileage… Acetone ignites easier than gasoline… Acetone is cheap… Acetone easily mixes with many liquids, including gasoline... HMMMM????? A cure for better mileage?

15. Ask Questions Can we improve gas mileage in our car?

16. Hypothesis Acetone improves gas mileage in automobiles. Prediction If we add acetone to gasoline, we will see an increase in gas mileage.

17. Experiment Remember: Experiments are designed to test the: HYPOTHESIS!!!

18. Experiment Control Group – Receives no experimental treatment Drive car 200 miles with just gasoline Experimental Group – Change only ONE variable from the control group Drive car 200 miles with gasoline and acetone mixture Independent Variable – Acetone in gasoline. Dependent Variable – Gas mileage

19. Analysis No significant improvement in gas mileage from 20mpg to 20mpg Reject hypothesis!

20. Why Peer Review? Lots of people trying to pass “stuff” as “science”… People try to make money off gullibility Example:

23. What’s wrong with these photos???

24. Old Wives Tales (Hypotheses we are used to hearing about…) 1.Listening to classical music during testing will improve test scores. 2.Spraying Windex on wounds makes them heal much faster. 3.Swimming after you eat will give cramps. 4.Cold weather makes you catch a cold. 5.Eating food from the floor is more likely to make you sick. 6.Cracking your knuckles gives you arthritis.