Spatial interpolation is the process of estimating values in locations that do not have measured values based on known values at other locations. There are several key elements to spatial interpolation, including control points which are locations of known values, the number and distribution of control points, and the type of interpolation method used which can be global or local. Interpolation methods can also be categorized as exact or inexact, and deterministic or stochastic, with stochastic providing assessments of prediction errors. Kriging is a specific geostatistical interpolation method that can assess the quality of predictions and estimates prediction errors.