Once you are able to use context clues, you won't have to rely on the dictionary as much as you did before. Often students will use a dictionary to look up unfamiliar words, get the definition, and forget the meaning very soon. However, using the clues force you to make an educated guess. This process help students truly learn a new word. Furthermore, students won't have a dictionary during a test, so it is a crucial skill, especially for ESL students.