A signal is an important clue to understanding the situation in which you find yourself. You have already learned to interpret many signals. When you were younger, you learned about traffic lights that warn you when to stop and let you know when it is safe to cross the street. You know that drivers must be careful to notice and respond to all kinds of signs and signals in order to arrive at their destinations safely.

In much the same way, writers who want to communicate clearly use words for signals. These signal words give the reader important clues about the content of the writing. They help the reader make the correct connections between ideas. In this way, the author assists the reader to look at things they way he does.