Available with Geostatistical Analyst license.
Some input datasets may have several points with the same x,y coordinates. These points are called coincident points.
The Geostatistical Wizard prompts you for a response when coincident points are encountered. However, the interpolation tools in the Geostatistical Analyst toolbox can use the Coincident points environment variable to control how coincident points will be handled. By default, the values of coincident points will be averaged.
The Coincident points environment variable is not honored by the Geostatistical Wizard since this setting applies only to the geoprocessing environment and the geoprocessing tools.
In kriging models, coincident points are used to estimate the measurement error term when describing the nugget.