Identifying global outliers using the Histogram tool

Steps:

1. Click the point or polygon feature layer in the ArcMap table of contents that you want to explore.
2. Click the Geostatistical Analyst arrow on the Geostatistical Analyst toolbar, click Explore Data, then click Histogram.

   If on the very left (the extreme minimum) or on the very right-hand side (the extreme maximum) of the histogram you see an isolated bar, it may be indicating that the point that the bar represents is an outlier. The more isolated from the main group of bars of the histogram such a bar is, the larger the likelihood that the point is indeed an outlier.