Scientific Inquiry

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Scientific Inquiry

• What is Science?

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What is Science?

• A body of knowledge
• A set of theories that describes the world
• A way of learning about the world
• A method to answer questions about the natural
  world

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How do Scientists Learn About the World?

1. Ask a question
2. Make a prediction
3. Test the prediction
4. Compare results to the prediction
5. Make a conclusion
6. Hypothesis is either rejected, or supported

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The Scientific Method-ask a question

• Only questions which can be answered through
  experiments.
• Examples of good scientific questions
• How does the amount of nitrogen fertilizer affect
  the height of pea plants?
• Does increasing the temperature of an enzyme
  increase its rate of reaction?

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Write a Good Scientific Question.

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Scientific Method-make a prediction

• Make a prediction
• A scientists prediction about the results of an
  experiment is called the hypothesis
• The hypothesis must be testable and specific and
  always written as a statement
• Hypotheses usually begin with I think that or
  Ifthen
• Example I think that the more fertilizer that a
  pea plant gets, the taller it will grow

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Scientific Method-test the prediction

• Controlled Experiments
• Used by Scientists to test their hypothesis
• Always have at least two groups
• Control Group- stays the same
• Experimental Group- changes, receives some sort
  of treatment

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How are the control group and the experimental
group different?

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Scientific Method-compare results

• Scientists analyze the data collected
• Data is information
• Compare the data from the control group with the
  experimental group
• Use statistics to see if there is significant
  difference
• Example- the pea plants in the experimental group
  grew an average of 18.3cm, while the control
  group grew an average of 12.6cm

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Scientific Method- make a conclusion

• Examine data, charts, graphs, to determine if the
  hypothesis is supported or rejected
• Could the differences be due to chance?
• Use statistics to tell

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Scientific Method- hypothesis rejected or
supported?

• If supported, repeat experiment to see if it is
  valid ( able to be repeated with the same
  results)
• If rejected, then come up with a new hypothesis
  and experiment, repeat the process

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Controlled Experiments- variables

• Three types of variables
• Independent- the thing that is different between
  the experimental and control group
• Dependent- the data you collect as your
  experiment progresses, depends on the independent
  variable
• Controlled- remains the same

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• I set up an experiment with 30 pea plants. I
  give 10 plants no fertilizer, 10 plants 5g. of
  fertilizer, and 10 plants 15g. of fertilizer.
  After 14 days I measure the height of the plants.
• What is the independent variable?
• The amount of fertilizer
• What is the dependent variable?
• The height of the pea plants
• What are the 2 controlled variables?
• The amount of soil and water
• What is the control group?
• Plants with no fertilizer
• What is the experimental group?
• The two groups of plants getting fertilizer

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What makes a good experiment?

• Large number of samples
• Only one independent variable
• Validity
• Conclusions based on evidence
• Is based on fact, not opinion

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Design an Experiment !

• Think of an experiment to test the hypothesis
  that sleeping more than 8 hours a night improves
  a students grades on Science quizzes!
• Control group
• Experimental Group
• Independent Variable
• Dependent Variable
• Controlled Variables