Figure 5 shows a typical example. One window shows data in graph form while the other shows a table. It's obvious if the two views are linked by color. If the informational view in the right window had a different color than it's corresponding object in the left view, the viewer will incorrectly form a nominal scale grouping. Ordered Organization Associate and selective perception provides only nominal scale classification.
Observers can see that one value of a variable represents a larger or smaller quantity than another.
In Figure 2a, for example, increased age could be represented by data points with increased brightness. Bertin considers the planar variables, brightness, size and texture variables as ordered while excluding shape, color and orientation. That is, the ratio of variable values maps directly to the ratio of the data values. In figure 2a, if age were represented by data points of different size, which is a quantitative variable, the viewer could immediately see which individuals were twice as old as others. While ordered data permit only relative magnitude of the represented quantities, quantitative variables support perception of ratios.