In this chapter, exploration of spatial variation in single variables available on grids is the focus. Methods outlined would be appropriate in, for example, analysis of single properties such as elevation or digital number in a remotelysensed image. While univariate methods are detailed here, it should be noted that there are multivariate versions of some of the methods described in this chapter. The methods described in Chapter 4 can also be applied to gridded data, as can those detailed in Chapter 5. The present chapter focuses on methods specifically designed for, or adapted for use with, gridded data. Some of the approaches outlined have a relatively long history, and the potential scope of this chapter is vast. Inevitably, the focus is on a restricted range of approaches that are used to highlight key concepts.