Sleuth_03

Are collected serially robustness against departures

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Unformatted text preview: bservations are collected serially. Robustness against departures from independence (cont.) t-tests are not robust to departures from independence! Example of Clustering (Grouping) We have n subjects in ea! of "ve di#erent PE classes %e response is weight loss over a set period of time We weigh ea! subject twice, but treat the data as if ea! measurement corresponded to two persons – NOT a good idea! Resistant Statistical Tools A statistical procedure is “resistant” if it does not give very di#erent results with or without a few outliers in the data, Example: %e median is very resistant to the presence of outliers, but the mean may be greatly a#ected Since t-tests are based on means, the...
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