Vocabulary Teaching and Learning Across Disciplines

       Middle level educators understand that vocabulary is at the heart of general language development and conceptual learning and is, therefore, a critical aspect of curricular programs in all disciplines at the middle school level. The extensive research base on vocabulary learning and teaching provides us with important guidelines that inform instruction (Harmon, Wood, & Hedrick, in press). In this research summary, we highlight relevant studies that support several key understandings of vocabulary learning and teaching. The following are six key understandings for all teachers across age levels and content areas.

·               Word knowledge is important for learning.

·               Word knowledge is complex.

·               Metacognition is an important aspect of vocabulary learning.

·               Effective vocabulary instruction moves beyond the definitional level of word meanings.

·               Vocabulary learning occurs implicitly in classrooms across disciplines.

·               Vocabulary learning occurs through direct instruction.

Word knowledge is important for learning

       Educators understand the importance of vocabulary, and few, if any, would omit vocabulary from their instruction. We know that a large vocabulary is an asset to readers; those who know many words are more likely to comprehend what they read. In fact, we have known for many decades that vocabulary size is a strong predictor of reading comprehension (Anderson & Freebody, 1981; Davis, 1944; Singer, 1965). However, the relationship between word knowledge and reading comprehension is complex and not easily described as one causing the other (Pearson, Heibert, & Kamil, 2007). Teaching unfamiliar words before students encounter them in a passage does not necessarily guarantee comprehension. Nonetheless, research indicates that there is a strong, positive, reciprocal relationship between word knowledge and reading comprehension (Baumann, Kame'enui, & Ash, 2003; National Reading Panel, 2000; RAND Reading Study Group, 2002). That is, vocabulary knowledge enables students to comprehend what they read, and the act of reading itself provides the opportunity for students to encounter and learn new words. Furthermore, the more words students know, the more likely they are to learn new words easily (Shefelbine, 1990). Conversely, students with limited vocabularies tend to read less and, therefore, have fewer exposures to new words in running text (Stanovich, 1986). Tremendous differences in word knowledge exist among students—differences that begin to appear at very young ages (Hart & Risley, 1995) and continue to impact learning as students move through school.

Word knowledge is complex

       The nature of vocabulary learning and acquisition is complex and involves several processes that can inform instruction. Nagy and Scott (2000) described five noteworthy components of word knowledge. First, they pointed out that word learning is incremental—that is, we learn word meanings gradually and internalize deeper meanings through successive encounters in a variety of contexts and through active engagement with the words. For example, the average tenth grader is likely to have a deeper and more sophisticated understanding of the term atom compared to the knowledge of an average fourth grader, who still has a more simplistic understanding of the term. We also know words at varying levels of familiarity from no knowledge to some knowledge to a complete and thorough knowledge, which serves us especially well in speaking and writing (Beck, Perfitti, & McKeown, 1982; Dale, 1965). It may be that, for some words, students may only need to have a general understanding of a term to keep comprehension intact. For other words, a deeper understanding may be necessary for students to successfully comprehend a passage.

       Another aspect of word knowledge is the presence of polysemous or multiple meaning words. Many words have different meanings depending upon the context in which they are used. This is especially evident in the various content areas such as mathematics, where polysemous word meanings differ greatly from the common usage of words (Durkin & Shire, 1991; Wood & Harmon, 2008; Rubenstein & Thompson, 2002). For example, a common word such as table represents an entirely different meaning in science texts when authors discuss the Periodic Table.

       A third aspect of word knowledge described by Nagy and Scott (2000) is the different types of knowledge involved in knowing a word. The types of knowledge include the use of words in oral and written language, correct grammar usage of words or syntactical knowledge, semantic understandings such as appropriate synonyms and antonyms, and even morphological understandings that involve correct usage of prefixes and suffixes. Surprisingly, more than 60% of words encountered in academic texts can be taught morphologically (Nagy & Anderson, 1984). In particular, Milligan and Ruff (1990), in their analysis of social studies textbooks used from elementary through high school, found that approximately 71% of the glossary terms contained affixes and roots that could be directly taught.

       A fourth aspect of word knowledge is the notion that learning a word meaning is inextricably related to knowledge of other related words. We do not learn word meanings in isolation; we learn word meanings in relation to other words and concepts. For example, knowing the concept of rectangle involves knowing about polygons, quadrilaterals, right angles, squares, and other related concepts. Finally, Nagy and Scott (2000) noted that word knowledge differs according to the type of word. Knowing the meaning of prepositions (e.g., if, under, around) differs greatly from knowing the meaning of specific science terminology, such as nucleus, proton, and neutron.