Graph designers have little influence over the conditions under which read a reader may a graph; for example, a degraded visual image may be caused by poor eyesight, re- duced image size, a multigeneration photo- copy, or a transparency rendering for an oral presentation(Wickens, 1992) Figure 3 contrasts two graphs, one that vio- lates the principles to be described in the fol lowing sections(Figure 3A) and one that follows those principles(Figure 3B) 2.1.1. Readers will need to detect all i cators, verbal labels, and quantitative labels.