How to detect influential observations in logistic regressiobn?
The documentation for the influence diagnostics says "the distributions of these diagnostic statistics are not known, so cutoff values cannot be given for determining when the values are large." To use these statistics, you plot them against an index and look for outliers.
What is an outlier? The answer depends on you, the analyst. An influential observation can be an important observation to explain what's going on in your data or it might be an aberrant case where something went wrong. Influence diagnostics tell you which cases are worth investigating, nothing more.
If some cases are much more influential than the rest, then go to the source and seek answers about those.
Check MODEL statement option OBSTATS in PROC GENMOD .
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ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.
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