Lecture 3 Properties of Summary Statistics: Sampling
Distribution
Slide 2
Main Theme How can we use math to justify that our numerical
summaries from the sample are good summaries of the
population?
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Lecture Summary
Slide 4
Setup
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Loss Function
Slide 6
Sadly It is impossible to compute the values for the loss
function Why? We dont know what the parameter is! (since its an
unknown feature of the population and were trying to study it!)
More importantly, the statistic is random! It changes every time we
take a different sample from the population. Thus, the value of our
loss function changes per sample
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A Remedy
Slide 8
Bias-Variance Trade-Off: Square Error Risk
Slide 9
Sample Mean, Bias, Variance, and Risk
Slide 10
Sample Variance and Bias
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In Summary
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But But, what about the distribution of our summary statistics?
So far, we only studied the statistics average behavior. Sampling
distribution!