This presentation describes both classical statistical and geostatistical methodologies designed to quantify qualitative information. Though the material presented is not heavily mathematical, the presentation is not simplistic. General equations and matrix notation are used in some sections. The equations are presented mostly for informational purposes, because calculations used in geostatistics tend to be tedious and very computer-intensive. This module presents an overview of techniques that can be used to transform a traditional geological reservoir description (a surface or 3D volume) into a mathematical reservoir.