The Scientific Method

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The Scientific Method
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What Is the Scientific Method?

• The scientific method is a process used to
  systematically investigate observations, solve
  problems, and test hypotheses.

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Why Do We Use the Scientific Method?

• The scientific method is a means of ensuring that
  experiments produce reliable information in
  response to a specific question.

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How Do We Use the Scientific Method?

• The 5 Steps to the Scientific Method

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Step 1 Identify the Problem

• What is the scientific question you are trying to
  answer?

Which stain is harder to remove from a cotton
shirt, ketchup or mustard?
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Step 2 Formulate a Hypothesis

• Make a prediction regarding the outcome of your
  experiment.

Hypothesis I think that a ketchup stain will be
easier to remove from a cotton shirt than a
mustard stain.
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Step 3 Create Perform the Experiment

• Give a detailed explanation of how you will
  conduct the experiment to test your hypothesis.

Be clear about your variables!
Be specific about how you will measure results!
Your procedures should read like a recipe!
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Dependent Independent Variables

• Dependent variable the part of the experiment
  that is affected by the independent variable
  THE RESULT!
• It depends on the independent variable.
• Independent variable is the part of the
  experiment that you intentionally change or
  manipulate
• only one independent variable can be tested at a
  time

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Controls

• Controls also called constants, the part of the
  experiment that is not being tested and is used
  for comparision
• there can be many controls in an experiment

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DRY MIX

• Dependent
• Responding ---- gt the response or RESULT of the
  experiment
• Y - axis
• Manipulated
• Independent ---- gt you intentionally change
  (manipulate)
• X - axis

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Ketchup Stain vs. Mustard Stain

• Materials
• 2 cotton t-shirts
• 1 tbsp of ketchup
• 1 tbsp of mustard
• 1 cup laundry detergent
• Washing machine

• Apply 1 tbsp of ketchup to a cotton t-shirt.
• Apply 1 tbsp of mustard to the other cotton
  t-shirt.
• Allow to dry for 30 minutes.
• Put both t-shirts into washing machine (warm
  cycle) and add laundry detergent.
• Remove once cycle is complete.
• Repeat washing cycle until stain is gone.

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Time to think!

• In this experiment what is the
• Independent variable?
• Dependent variable?
• Controls?

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Step 4 Record Analyze Data

• Record observations, data, and results.
• Your journal should contain measurements and
  written notes about what you are sensing (seeing,
  hearing, etc.) about your experiment.
• Display your data using graphs and charts.
• Modify the experiment if needed and repeat
  experiment with modifications.

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Ketchup Stain Vs. Mustard Stain

• Observations
• After first washing cycle, the ketchup stain was
  completely gone.
• The mustard stain was lighter but could still be
  seen on the cotton t-shirt.
• After second washing cycle, the mustard stain was
  even more light, but could still be seen.
• After third washing cycle, the mustard stain was
  completely gone.

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Step 5 Communicate the Results

• Answer your problem statement.

Scientists draw conclusions by examining the data
Two possible outcomes The experiment supported
your hypothesis and can be regarded as
true, Or The experiment disproved the hypothesis
as false
Does your conclusion agree with the hypothesis?
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Ketchup Stain vs. Mustard Stain

• Conclusions

The ketchup stain was easier to remove from the
white cotton t-shirt because it only took one
washing cycle to remove while the mustard took
three washing cycles to remove.
And the winner is
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Scientific Method Review

• 5 steps

Step 1 Identify the Problem
Step 2 Formulate a Hypothesis
Step 3 Create Perform the Experiment
Step 4 Record Analyze Data
Step 5 Communicate the Results