Multivariate descriptive displays or plots are designed to reveal the relationship among several variables simultaneously. Bivariate and multivariate maps encode two or more data variables concurrently into a single symbolization mechanism. Their purpose is to reveal and communicate relationships between the variables that might not otherwise be apparent via a standard single-variable technique. There are basic characteristics of the relationship among variables, such as the forms of the relationships, the strength of the relationships, and the dependence of the relationships on external (usually to the pairs of variables being examined) circumstances. Therefore, these multivariate plots or maps are inherently more complex, though offer a novel means of visualizing the nuances that may exist between the mapped variables. As information-dense visual products, they can require considerable effort on behalf of the map reader, though a thoughtfully-designed map and legend can be an interesting opportunity to effectively convey a comparative dimension. Examples of multivariate plots include enhanced 2-D scatter diagrams, 3-D scatter diagrams, contour, level, and surface plots, and high-dimensional data plots