03-26-2016 06:25 PM
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.
03-27-2016 02:43 AM
03-27-2016 03:16 PM
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.