The University of Iowa

The Importance of Word Choice in Explicit Vocabulary Instruction

Open book with glow

There is great potential for teaching vocabulary using words from a book if teachers carefully consider which high-priority vocabulary words from the text to use during explicit vocabulary instruction.


Posted on: October 17, 2017

Editor’s Note: This is the first of a two-part series on vocabulary instruction.

In a classic literacy study supported by a recent meta-analysis (Pfost et al., 2014), Stanovich (1986) explains a phenomenon in the development of reading comprehension referred to as “The Matthew Effect.” According to Stanovich, the “rich” (proficient readers with high oral language skills) get richer, and the “poor” (those who lack proficiency and accordingly have a smaller oral vocabulary) become poorer. In other words, students who begin elementary school with deficient oral vocabularies will most likely experience slower reading growth in relation to students possessing a more robust knowledge of words. Educators can help reduce this gap in vocabulary knowledge and, thus, reading comprehension through purposeful planning and implementation of vocabulary instruction.

Explicit Versus Implicit Vocabulary Instruction

As students read independently or listen to oral language, they often encounter unknown words. Students who have been taught strategies for determining the meanings of new words will be better equipped to comprehend texts and discussions, as well as acquire academic language. This type of word learning is incidental, as it occurs within an activity not designed specifically to expand one’s vocabulary. Although implicit word learning is essential to increasing the number of words a child knows, it cannot be the sole vocabulary instruction a child receives (Marulis & Neuman, 2010).

Explicit vocabulary instruction, which is the direct and purposeful teaching of new vocabulary words, complements implicit vocabulary instruction by (a) modeling for students how to acquire more than a superficial understanding of words essential to their comprehension of specific texts and (b) engaging them in meaningful practice with such words. If the goal of implicit instruction is to broaden the number of words a child knows, the goal of explicit instruction is to deepen knowledge of important words, such as learning the different ways a word can be used, the relationship among related words, or the appropriateness of a word for a particular context (Nagy & Herman, 1987).

Selecting Words for Instruction

To ensure that word learning is effective and targeted, we must meticulously plan explicit vocabulary instruction. The first step is to determine which words are important enough to warrant exclusive instructional time. Admittedly, these decisions prove to be daunting for educators of all levels of experience because you may identify numerous words with which students will struggle in a text. Educators can use the following three-tiered system (Beck et al., 2013) to prioritize and select vocabulary words to be used in direct instruction.

Table 1. Three Tiers of Vocabulary Words for Instruction

  Definition Examples
Tier I Words used orally every day; usually taught in younger grades ball, dog, walk, read
Tier II Words that appear in written, rather than oral, language; generalizable or "travel well" across many content areas disparate, complex, establishment, principle
Tier III Words that are domain-specific; closely tied to content knowledge personification, integer, caste system, ozone, chromosome

Because Tier II words can be applied to many topics or contexts and often have multiple meanings, the deep understanding of these words is most useful to elementary students. By contrast, middle and high school content area teachers often find that Tier III words are critical for academic success because they appear frequently in subject matter text and are necessary for understanding the content students are expected to learn. However, the number of unfamiliar Tier II or Tier III words in a text can make explicitly teaching them all an impossible or overly time-consuming task. It is necessary to consider which words are more important to teach.

Characteristics of High-Priority Words

To identify the most important vocabulary for explicit instruction, consider whether a word:

  • Enables students to understand a text
  • Supports comprehension and application of major themes and central ideas
  • Expands students’ vocabulary by providing them with more specific word choices for a commonly used word (Beck et al., 2013)

For example, when studying To Kill a Mockingbird (Lee, 1960) in an English language arts and reading class, students may not know the Tier II words disapprobation, peculiar, or scowl. In order to understand Jem and Scout’s (the children’s) motivation in Chapter 15 to leave the house and search for their father, Atticus, students would need to understand that several of his preceding actions seemed strange because they contradicted his usual behavior. Students might encounter peculiar in science and social studies as well, and could use this word in their writing to replace the nonspecific and overused word weird. Hence, peculiar would be an appropriate target for explicit vocabulary instruction. On the other hand, the fact that Jem scowled when his sister objected to leaving the house at night is not essential to understanding the novel’s major ideas. Therefore, teaching students strategies for incidental word learning, such as using context clues, might be more appropriate for this Tier II word. Unlike scowl or peculiar, disapprobation is not as commonly used in speech or print. However, its use in the novel is accompanied by Atticus’ relevant and child-friendly explanation that the teacher might “get after him” for reading to Scout each night. There is already adequate support for students to understand this word, so it would not require additional instruction.

If you feel unsure about how to identify Tier II vocabulary words, this Academic Word Finder from Achieve the Core is a helpful resource.

Even though some children come to school knowing fewer words than their peers, we can begin to lessen this disparity through a combination of effective implicit and explicit vocabulary instruction. Selecting important words for direct instruction is a significant first step in deepening students’ vocabulary knowledge and increasing reading comprehension. If we purposefully target words based on (a) the students’ experience within a certain text and (b) each word’s potential applications to a variety of contexts, the time spent teaching words to students will be invaluable to their growth as readers.

Check back to the blog on October 31 for the second post on vocabulary instruction.


Beck, I. L., McKeown, M. G., & Kucan, L. (2013). Bringing words to life: Robust vocabulary instruction (2nd ed.). New York, NY: Guilford.

Lee, H. (1960). To kill a mockingbird. Philadelphia, PA: Lippincott.

Marulis, L. M., & Neuman, S. B. (2010). The effects of vocabulary intervention on young children's word learning: a meta-analysis. Review Of Educational Research, 80(3), 300-335. doi:10.3102/0034654310377087

Nagy, W. E., & Herman, P. A. (1987). Breadth and depth of vocabulary knowledge: Implications for instruction. In M. McKeown & M. Curtis (Eds.), The nature of vocabulary acquisition (pp.13-30). New York, NY: Psychology Press.

Pfost, M., Hattie, J., Dorfler, T., & Artelt, C. (2013). Individual differences in reading development: a review of 25 years of empirical research on Matthew Effects in reading. Review of Educational Research, 84(2), 203-244. doi:10.3102/0034654313509492

Stanovich, K. (1986). Matthew Effects in reading: some consequences of individual differences in the acquisition of literacy. Reading Research Quarterly, 21(4), 360-407. doi:10.1598/RRQ.21.4.1