It’s helpful to compare the hierarchy necessary in good sign design to a chain of thought.
A chain of thought is the logical sequence of the parts of an argument. It is a succession of “points” on a path of reasoning. That’s why we call it a line of reasoning—because there should be a logical order to the parts.
Good sign design is also a sequence of information. It should be presented to viewers like the beads on a string. They should be able to easily view the information in a logical order. They should be able, without thinking, to read first what we want them to read first, to read second what we want them to read second, and so on. We must create a visual hierarchy, in descending importance.
A good sign design’s plan always includes the order in which the parts are to be viewed. If we do not control this sequencing of visual information, the composition will likely be easily ignored, just like an illogical, incoherent argument is ignored.