Sampling Distributions

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Sampling Distributions
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What is a sampling distribution?

• Grab a sample of size N
• Compute a statistic (mean, variance, etc.)
• Record it
• Do it again (infinitely)
• The resulting distribution is a sampling
  distribution
• Articulation of the Sample Space

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Concept of the Effect Size

• Related to Study Outcome
• Indicates relations between X and Y (relations
  between IV and DV)
• Indicates magnitude of effect
• Size of effect, Effect Size

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Two Common Effect Sizes

• Correlation, r

• Standardized Mean Difference, d

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ES Sampling Distributions

• If delta 0, distribution approx normal
• If rho 0, distribution approx normal
• If not zero, distributions are not normal.
  Customary to apply fixes for this (discussed
  later).

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Boxplot1
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Boxplot 2
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Boxplot 3
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Empirical (Monte Carlo) Sampling Distributions

• Examine SAS programs
• Merge results from different runs

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Introduce Homework 1
Download it. Read it. Does it make sense? Can you
do it?