Measurement and Analysis

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Measurement and Analysis
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Accuracy and Precision

• Accuracy, again, is how close a data point is to
  the actually true data point
• Think of the center of a target board!
• Precision is how close the data points are to
  each other
• Think if all the darts hit the same point

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Accuracy and Precision

• Data Points can be
• Very accurate and very precise
• Not accurate and very precise
• Very accurate and not precise
• Not accurate and not precise
• Try to Identify the following examples.

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Go to the Board!
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How does Sample Size affect accuracy of an
experiment?

• The higher the sample size..the more accurate
  you data points will be.
• Instead of having a sample size of 10 people for
  example..you could have a sample size of 10,000
  people.you will be much more accurate.
• You will be more likely to represent accurate
  results if you do this!

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How to calculate Percent Error

• There is ALWAYS error in experimentation.
• It is our job to eliminate as much error as
  possible.
• Percent Error tells you how much error is in your
  lab procedure.
• Error (True Value-Experimental Value)
• True Value

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Back to the board

• Example Problems