The Importance of Vocabulary
in Reading Comprehension

The Importance of Vocabulary in Reading Comprehension
Kendra Wagner, M.Ed.
     Most researchers in education believe that vocabulary knowledge and reading comprehension are closely related, and many studies have shown the strong correlation between the two. Some have indicated it may even be as much as 75% of the equation.   If we do not understand the meaning of a mere four words on a page of a novel, we move away from the author’s message and the joy of reading.  Understanding the meaning of words involves understanding not only common words but multiple meanings, nuances, figures of speech, and borrowed words from other languages.

A strong vocabulary has been linked consistently with overall reading proficiency and the ability to think at higher, more abstract levels.  A child’s ability to read, speak, write, and think inevitably is influenced by his vocabulary.  Words cannot be separated from ideas; after all, we do use WORDS to think!

Helping Students Increase Vocabulary

OK, so vocabulary is important.  How can we help kids increase the number of words they can read and understand?   We can do so by giving them plenty of chances to read, in a variety of genres.  That can be difficult to do with the tightly scheduled days of the modern classroom.  The good news is that as little as 15 minutes several times a day can build their abilities and their vocabulary over time.   

Another way you can support growing vocabularies is to stretch students into books that have increasingly more difficult words when you give them a chance to read,.  Help each student choose books that are a challenge, but are not at their “frustration level” (a book that is too difficult for the student to read independently). 

When you select books for reading aloud to your class, choose ones with rich, varied vocabulary.  Even children’s picture books are full of such words (Hayes and Ahrens,1988).  Building on this idea of “just the right book”, we must remember that words children hear in everyday conversations with peers and adults, TV shows, and even political speeches are not the same level of complexity as those in the pages of books.  When talking to a friend I might use the phrase, “I was shocked” but, in a book, I might find more colorful, complex words like “mortified”.  Researchers call this “academic language.”  

Don’t Forget Effective Vocabulary Instruction in the Classroom
Another vital component in growing children’s vocabularies is effective classroom instruction. According to Michael Graves (2000), there are four components of an effective vocabulary program:

  1. wide or extensive independent reading to expand word knowledge [as already mentioned]
  2. instruction in specific words to enhance comprehension of texts containing those words
  3. instruction in independent word-learning strategies
  4. word consciousness and word-play activities to motivate and enhance learning

Often when children ask an adult what a word means, we say, “Use the context.” Consider this child listening to a story:

Ella watched as Nora got smaller and smaller and finally vanished.
And the child is wondering….

Is vanished:

    1. more like disappear or go away?
    2. is it complete (might she be microscopic?)
    3. always gradual?
    4. unexpected?
    5. deliberate?
    6. restricted to people?

Context only works 50% of the time in any reading material. We can better describe words by coming up with “kid-friendly” definitions, that include what the word is NOT, a synonym, and another situation in which it would be used.  So, you could say,

Vanished is when something or a somebody goes away suddenly. It usually is mysterious too. It is not when someone suddenly appears. Your coat could vanish from the playground, even though you saw it a minute ago and someone took it in to Lost and Found. A genie can vanish from the air back into his bottle.

All Books Are Not Created Equal When It Comes to Building Vocabulary

Vocabulary’s importance can be overlooked in the daily classroom and the cheerleading about reading that kids hear from teachers.  Teachers sometimes tell parents that as long as their child is reading, then there is cause for celebration. But one book is not equal to another.  A page of Diary of a Wimpy Kid (  has very few words that stretch a child’s vocabulary collection, but a page of Harry Potter and the Sorceror’s Stone ( has seize, pensive, arduous, and managed. In the same way, many of the books in the Goosebumps series ( and others can initially entice a student to read but, if read exclusively, develop a child’s taste for short sentences, simple sentence structure, easy vocabulary, uncomplicated para­graphs, and shallow simple plots. This won’t help him make the transition to decent liter­a­ture; it may teach him to turn away from anything that makes his brain work too hard.

Combining a diet of “just right” books with those that give a bit of challenge to the reader and offering a wide variety of reading material will go a long way toward supple­ment­ing effective vocabulary instruction in the classroom.  We need all these elements since vocabulary growth occurs from both direct instruction and indirect exposure.

Bibliographic references cited in this article are available upon request from the editor at

Kendra Wagner, M.Ed., teaches students and teachers about literacy in Seattle and beyond. She specializes in children with learning disabilities in her private practice as an academic therapist. She is on the Board of Directors of International Dyslexia Association, and consults in schools about RTI and implementing research-based practices in reading and writing.