Designers must also take care to visually differentiate symbols representing different object types. Discerning a particular icon within a screen full of similar icons is as difficult as discerning a particular word within a screen full of words.

• 设计师必须注意让视觉上不同的符号代表不同的对象类型，在一个布满相似图标的屏幕上辨认某个特定图标与在一堆文字里辨认某个字一样困难。