Vocabulary knowledge is highly correlated with reading comprehension and general academic success. Oxford Dictionaries defines vocabulary as “the body of words used in a particular language” (Oxford Dictionaries, 2013, para. 1). Vocabulary knowledge can be demonstrated in two ways: receptively or expressively. Knowledge of the words we see and hear would be described as the individual’s receptive vocabulary. Expressive vocabulary consists of the words that are used to convey information, by either writing or speaking. Typically, receptive vocabulary is larger than expressive vocabulary. Although individuals may understand the general idea of a word in their receptive vocabulary, they might lack the knowledge of the true definition that would be needed in order to use the word in their expressive vocabulary (Kamil & Hiebert, in press). Vocabulary development is important for a variety of reasons.
Children’s vocabulary development is important from an early age. Studies have shown that children who are regularly read to have larger vocabularies and better success at decoding words when reading (Burgess, Hecht, & Lonigan, 2002). Children’s vocabulary at age three is a strong predictor of their language and reading comprehension in third grade (Hart & Risley, 1995). Further, it has been shown that children with poor vocabulary skills struggle with reading comprehension.
Not only does vocabulary play a crucial role in reading comprehension, it is also highly correlated with academic success (Lehr et al., 2004). As students progress through the grades, the vocabulary necessary to succeed in higher grades becomes more extensive. Typically, academic vocabulary demands appear in children’s 3rd and 4th grade books (Chall, Jacobs, & Baldwin, 1990; Chall & Conard, 1991). Academic vocabulary is the vocabulary that is used in textbooks, lectures, and on tests. Without the knowledge of the academic language, it is very difficult to understand the concepts or apply what is being taught. Often, students who have trouble with academic vocabulary fail to comprehend classroom vocabulary, which negatively impacts their academic success.
Bishop, Yopp, & Yopp (2009) emphasize that vocabulary instruction needs to be implemented early and in all areas of the curriculum. When children enter...