Hart and Risley (2003) found that gaps in vocabulary size are evident as early as preschool age, with three-year-olds from “professional” families knowing twice as many words as three-year-olds from welfare families. Research indicates that explicit instruction of vocabulary is needed both to address this gap and to teach difficult words—those that “represent complex concepts that are not part of the students’ everyday experiences,” according to Center for the Improvement of Early Reading Achievement (CIERA 2003).
Recommendations for effective instruction
Vocabulary instruction helps with both fluency and comprehension, since the more words readers know, the less time they need to spend figuring out the text and the more time they can spend focusing on what the text means. Hirsch (2003) notes that students who know 90 percent of the words in a text will be able to understand its meaning and use that understanding to begin to learn the other 10 percent of the words. Students who do not know 90 percent of the words in a text, on the other hand, fall “further behind on both fronts.” He writes: “They missed the opportunity to learn the content of the text and to learn more words.”
Learning words indirectly—by talking with adults, listening to adults reading to them, and reading extensively on their own—will also help students build their vocabulary. Direct and indirect teaching of vocabulary will help students gain at least 5,000 words per year, according to Hirsch (2003), who estimates that a twelfth grader needs to know between 60,000 and 100,000 words to score well enough on the verbal portion of the SAT to get into a selective college.
This research review was prepared for the Center for Public Education by freelance writer Eileen M. O'Brien with additional editorial contributions from Sally Banks Zakariya. Much of O'Brien's work has focused on access to quality education for disadvantaged and minority populations. She has a master of public administration from George Washington University and a bachelor of science degree in psychology from Loyola University of Chicago. Zakariya, a free-lance writer based in Arlington, Virginia, is former editor-in-chief of American School Board Journal and director of publications for the National School Boards Association.
Posted: March 6, 2009
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