A primary objective of many exploration programs is to find structural features or anomalous areas as targets for more detailed exploration. Defining what is anomalous may be subjective, so that rigorous mathematical methods are not always available. A variety of graphical display techniques can be applied to this problem.

The essence of the graphical approach is to display data in such a way that unusual patterns may be easily detected visually. Since many types of data are acquired in exploration, different methods are used in different situations. It is advantageous to display a set of data in more than one way, as distinct patterns may be visible in each.

The graphical approach is particularly useful in regional surveys, where large areas and large volumes of data are involved. The main requirement in regional surveys is to quickly scan large geophysical and/or geochemical data files to define smaller areas for more detailed exploration.