Next Steps: Writing the Hypothesis,

and Creating An

Experimental Design

For Science Fair

What is a Hypothesis?A hypothesis is a prediction about the outcome of an experiment based on the experimenter’s prior experience and research. It attempts to give a scientific reason why a particular observable outcome will occur.

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A Hypothesis Has 3 parts:

The independent

variable• Part of the

experiment that is purposefully changed

• Begins with the word “If.”

• If children get at least 8 hours of sleep…

The dependent variable

• Part of the experiment that is the predicted effect

• Begins with the word “then”

• then they will perform better on tests…

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The researched

reason• Thoughtful

explanation as to why a predicted effect will occur

• Begins with “because”

• because rest lets the body heal and refresh.

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To write a good hypothesis

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1. Keep it simple and concise, be as specific as possible. Write the hypothesis in 1 sentence.

2. Don’t use words like I, think, believe, all, never, sometimes – they make the hypothesis too broad and personalize it.

3. Make sure it can be tested by getting numerical data.

http://iqa.evergreenps.org/science/resources/hypotheses/3-step-hypothesis-writing.html

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What Are Some Examples?

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1. If candy bars in a store are displayed at eye level, then they will sell better than those at the bottom of a display because people will be more likely to notice them.

2. If a cold tablet is placed into water that is stirred, then the tablet will dissolve faster because stirring increases solution rate.

3. If students using backpacks are in high school, then the backpacks will be heavier than those of middle schoolers because they have heavier textbooks.

http://www.allstoredisplays.com/assets/images/5-shelf-wood-candy-display-maple.jpg

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Don’t forget!1. A hypothesis can’t be proven

true. An experiment can only show if a hypothesis is supported or not.

2. Hypotheses are only accepted on a trial basis until a more supported hypothesis is written.

3. Unsupported hypotheses are still valuable since they help eliminate false ideas and explanation.

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How Do You Make An Experimental Design?

For Science Fair

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Fill Out the Experiment SheetStep 1

Select a category-See Proposal Form.

Step 2Write a working

title as a question.

Step 3Write down all the variables.

Step 4State 4 or

more constants

Step 5: control?

compared to?

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Write the hypothesis.

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Fill Out the Experiment SheetStep 1

Select a category-Human Behavior

Step 2Write a working

title : What Could Be Sweeter?.

Step 3:VariablesIV: shelf

placementDV: # candy sold

Step 4: Constants:same candy, price, store, size of bag

Step 5: Controlcompare to

different shelf

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If m&m’s candies are put on eye level and a bottom shelf, then the eye level ones will sell better because they will be noticed more.

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Remember to Add How Data Is Measured

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• Name the tools with which the final outcome will be measured

• Inventory receipts• Triple beam balance• Ruler• Thermometer• voltmeter

State the unit of measurement of the outcome. • Dollars• Grams• Centimeters• Degrees Celsius• volts