Vocabulary size predicts comprehension, but learning new words is especially hard for students who come to school with small vocabularies or limited knowledge of English.
What's the Idea?
Students who enter school with limited vocabularies, especially English language learners, often struggle to understand what they read because they are unfamiliar with many of the words they encounter. This barrier hampers their learning in all the subjects they study. The consensus of researchers and educators today is that such students need explicit vocabulary instruction.
What's the Reality?
Now, as in past decades, most teachers devote little time to explicit vocabulary instruction. Teachers are already under the gun to cover more material than time permits, and they are stymied by the need to devote extra time to vocabulary. Moreover, teachers face the challenge of identifying which words are most important for their students to learn, especially given the large gap in vocabulary size between students with poorly educated or non-English-speaking parents and their more advantaged peers.
What's the Research?
The research shows a strong relationship between vocabulary size and reading comprehension level; moreover, that relationship grows stronger as students progress through school (Snow, Porche, Tabors, & Harris, 2007). Because students who know many words can comprehend what they read, they continue to increase their vocabularies and content knowledge through reading. The opposite holds true for students with limited vocabularies, especially English language learners (Blachowicz, Fisher, Ogle, & Watts-Taffe, 2006).
Building vocabulary is more difficult than it might seem. Vocabulary signifies more than a list of words—it is a proxy for content knowledge. Learning new words often involves learning new ideas and information; memorizing definitions is not the same thing (Stahl & Fairbanks, 1986). Researchers concur that to "own" a new word for the long term, the learner must see and use the word multiple times in several contexts. The question is, How can teachers accomplish this goal efficiently?
Researchers have studied a variety of strategies to help students expand their vocabularies. In one such study, Beck and McKeown (2007) exposed kindergarten and 1st grade students to read-aloud trade books chosen because they included sophisticated words that struggling readers would be unlikely to learn on their own. The students had opportunities to discuss the books, hear the words explained in the context of the story, and hear the words used over the next few days. They learned more words than students in the comparison group, who participated in traditional read-alouds.
Carlo and colleagues (2004) tested the effects of a vocabulary enrichment intervention in which engaging texts and activities were used to teach 5th grade students strategies for analyzing new words using context clues and knowledge of root words and cognates. Students read newspaper articles, diaries, and histories about immigrants' experiences followed by daily work in small groups on such tasks as filling in missing words, making word associations, and playing charades. In classes randomly assigned to the intervention, both English language learners and native English speakers outscored comparison students on several measures of vocabulary development, including depth of knowledge and understanding of multiple meanings.
No one strategy can do the job alone, however. Because different kinds of words require different approaches— and students' needs vary by age, background knowledge, native language, and motivation—teachers must know and be adept in selecting among multiple strategies (Blachowicz et al., 2006).
Students at the secondary level need to expand their vocabularies rapidly to comprehend the multiple subjects they are learning. This challenge is especially intense for English language learners. Even those labeled as fluent English speakers, whose gaps in English may not be readily apparent, often struggle to develop the academic vocabulary they need to be successful (Butler & Hakuta, 2006).
Across grade levels, teachers get conflicting advice about which words to focus on. Some researchers argue that struggling students should be introduced early on to interesting, sophisticated words, partly to engage their interest and partly to help them catch up to their more advantaged peers (Beck & McKeown, 2007). Some argue for subject-specific academic words, such ascircumference and pollination (Marzano & Pickering, 2005), and others for words that cut across disciplines, such as synthesize or infer (Coxhead, 2000).
According to one synthesis of best practices for English language learners, the core reading program is a good place to begin choosing words for instruction in the elementary grades (Gersten et al., 2007). Others, however, point out that most basal reading books have little informational text and are therefore of limited help in building vocabulary or background knowledge (Walsh, 2003).
Whichever words teachers choose to teach, researchers agree that they need to provide a variety of structured opportunities for students to encounter and use new words in authentic and engaging contexts. The essential strategy is providing opportunities for students to practice using new words through reading, writing, speaking, and especially conversations led by teachers (Carlo et al., 2004).
What to Do?
Students grasp the full meaning of words gradually, with repeated use and varied contexts that illustrate how meanings can change. Whether the word is of or revolution, students cannot understand its meanings and usage without repeated practice and feedback. Conversations with teachers and peers that home in on vocabulary are one key element. Other elements include associating new words with pictures, creating semantic maps that show relationships among words, playing word games, and when appropriate, linking new words to students' native languages.
Devoting sufficient time to these activities can happen only if all teachers come on board and integrate vocabulary development into their instruction throughout the day. For example, elementary teachers might pick informational texts and stories with rich vocabulary as opportunities to learn new content and new vocabulary, along with careful attention to strategies that support learning the new words. Secondary teachers might use science experiments and movies, as well as written text, as sources for zeroing in on vocabulary development.
Without such concerted, schoolwide efforts, the achievement gap between students with limited vocabularies and their peers will continue to expand.
