Expectation and context heavily bias what we perceive. I argue that, to find the right answers, we need to know about the very nature of seeing itself. When mapping from data to image, retaining the elements is essential to the problem. Figure 1, shows VisualMine's representation of different levels of cash flows between regions of Italy, transformed into a 3D spread of differently colored pipes that help identify extreme instances indicative of money laundering. The former is a complex subject in its own right.
Translation usually entails loss and distortion, as well as amplification.
The key is to amplify and maintain what is essential to a given need. Most people do not know Africa has almost four times the land area of the United States. In mapping the surface of Earth onto a flat surface, it is possible to preserve only certain geometric relations. The commonly used Mercator projection, which preserves angles and is thus useful for navigation, greatly distorts sizes and is therefore not useful for understanding comparative land areas. The very mathematics of seeing require the viewer to make assumptions.