The Scientific Process

By Mr. Lin

What is Science?

• Science is simply the solving of problems in our natural world.

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How Do We Solve Scientific Problems?

• We use a step-by-step process.

– This process is called the “Scientific Method.”

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Scientific Method: Step #1

• Question

• No question, no point to experiment, no science.

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Scientific Method: Step #2

• Hypothesis– An educated guess to

answer the question.– MUST BE TESTABLE.

• Use “If . . . then . . .”

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Good Hypotheses• If I place a rock into

water, then it will sink.

• If I use a prism, then light will be split into many different colors.

• If my mom adds sugar to cereal, then my sister will eat more.

• If my class gets rid of “transition time” in class, then they will get more recess.

Image Courtesy of http://www.physics.ohio-state.edu/~gilmore/images/collection/misc/prism.gif

Scientific Method: Step #3• Experiment

• Experiments often have 2 parts.

– One setup where everything is left alone• This is called the “Control.” • Absolutely nothing is change.

– And another setup where only one thing is changed.• Constant: Anything that never changes between the two setups• Independent Variable: The one thing you changed in the second

setup.• Dependent Variable: What ends up happening because you

changed the Independent Variable.

Confused?

• Let me walk you through a simple experiment.

Does Salty Water Freeze As Fast As Fresh Water?

Sample Question

If I add one teaspoons of salt to one glass of water, then it will

freeze slower than one glass of fresh water.

Hypothesis

The Experiment

Experiment

• Independent Variable:– The ONE (and only

one) thing we make different from the control.

• Dependent Variable:– What happens

because of the independent variable

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Independent Variable Versus Dependent Variable

Scientific Method: Step #4

• Observation

• Use your five senses (seeing, hearing, touching, tasting, and smelling) to notice any dependent variables.

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Scientific Method: Step #5• Collect Data

• Take notes. Jot down interesting numbers and observations.

Scientific Method: Step #6

0

5

10

15

20

25

30

35

40

FreshWater

SaltWater

• Analyze

• Make some sense out of the data. – Make graphs– Draw pictures– What can you

infer because of the data?

Min

utes

nee

ded

till f

roze

n

Scientific Method: Step #7• Conclusion

• What is the answer to your question based on the experiment.– Do you need to

perform more experiments?

– Are there new questions?

– Are there new hypotheses?

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Scientific Method: Summary • Question• Hypothesis• Experiment

– Control– Constants– Independent Variable– Dependent Variable

• Observe• Collect Data• Analyze• ConclusionImage Courtesy of

http://www.hmc.psu.edu/diabetes/Photos%20and%20Graphs/j0400425.jpg