Enhancing Children's Vocabularies

Abstract

In an old study of pupils in grades 1 to 9, vocabulary correlated .91 with mental age (IQ) on the Stanford Revision of the Binet-Simon IQ scale (Terman 1918). Miner (1957) found, across twenty-one studies, a median correlation of .83 between the vocabulary subtest score and the general intellectual functioning score. Thorndike (1973) found, across fifteen countries, that the average correlations between vocabulary and reading comprehension were .71 for ten-year-olds, .75 for fourteen-year-olds, and .66 for eighteen-year-olds. The commonly accepted correlation between IQ and academic achievement is .70, with a median in the range of about .90 at Grade 1 to about .50 for college students. Vocabulary is central to IQ. Also, vocabulary knowledge correlates almost .50 with mathematics computation, slightly higher with mathematics problem solving, and higher with nearly all other academic subjects in the curriculum. Thus it is clear that vocabulary is vital to IQ, to general intellectual functioning, to reading comprehension, to academic achievement in general, and to achievement in other subjects in the curriculum in particular. Dale, O'Rourke, and Bamman (1971) interjected a note of caution about the kind of vocabulary gains that might reasonably be expected. Conversely, they indicated that any motivated person can increase his or her working vocabulary 10 percent by concentrating on those words, parts of words, and expressions that are only partly known. Surprisingly, the results of experimental efforts to enhance children's vocabularies have been equivocal at best (Royer 1983; McKeown, Beck, Omanson, and Popie 1985). Improving reading comprehension through vocabulary instruction has also proved equivocal (Jenkins and Dixon 1983; Graves 1986; Stahl 1986). Nagy (1988) noted that few people have had the intense, pro-