- The size of the task. The number of words that students need to learn is exceedingly large.
- The differences between spoken English and written, or "literate" English. The vocabulary of written English, particularly the "literate" English that students encounter in textbooks and other school materials, differs greatly from that of spoken, especially conversational, English. Students-both English language learners and those for whom English is the first language-may have limited exposure to literate English outside of school.
- The limitations of sources of information about words. The sources of information about words that are readily available to students-dictionaries, word parts, and context-pose their own problems. Each can be difficult to use, uninformative, or even misleading.
- The complexity of word knowledge. Knowing a word involves much more than knowing its dictionary definition, and simply memorizing a dictionary definition does not guarantee the ability to use a word in reading or writing. Adding to the complexity is the fact that different kinds of words place different demands on learners.
The Size of the Task
Although there is still debate over exactly how many and what words are essential for students to learn so as to become skillful readers, there is no question that skillful readers learn words by the thousands. There is also no doubt that without instructional intervention, the vocabulary gap between more and less skillful readers continues to widen over time.
We know that, on average, students add 2,000-3,000 words a year to their reading vocabularies. This means that they learn from six to eight new words each day — an enormous achievement. Individual differences in vocabulary size also involve large numbers. Some fifth-grade students may know thousands more words than other students in the same classroom. As a teacher, you know the difference this can make: students who know the meanings of many words catch on to and understand new ideas and concepts much faster than do those students with limited vocabularies.
Early in children's lives, differences in word knowledge levels begin to appear. This, in part, is due to the varying range of words children are exposed to within their homes and communities. Exposure to new words can differ dramatically among the children of families from different socioeconomic classes. It has been shown, for example, that young children of parents with jobs classified as "professional" can be exposed to 50 percent more words than are children of parents classified as "working class," and to twice as many words as children of parents who receive welfare support. This finding does not mean that all, or even most children from low sES backgrounds are condemned to lives of linguistic poverty. Rather, it underscores the importance of finding ways to provide children with more activities that promote language development and vocabulary growth, beginning in the earliest days of school. Children whose homes have not prepared them for the variety of English necessary for educational success can learn to master this language through well-designed school experiences.
The Differences Between Spoken English and Written English
Most spoken language, and especially the language of face-to-face conversation, is less rich and varied in vocabulary use than is written language. This is partly because speakers have a variety of communicative tools at their disposal — gestures, tone of voice, and facial expression — that are not available to writers. In addition, conversations between friends involve shared knowledge, which makes precise communication possible without precision in wording; "You know who" can identify the subject of a remark as precisely as a detailed physical description. In conversation, accuracy of communication depends more on feedback from listeners than on getting what is said exactly right.
In writing, and especially in literate writing, the primary communicative tool is precision in word choice. In fact, a conversation among college-educated adults contains, on average, less rich and varied vocabulary than does a typical children's book. The language of television is sometimes more varied than everyday conversation, but it seldom matches the level of language used in children's books.
The differences between spoken and written English can pose major problems for students learning English, whose vocabulary difficulties sometimes can be disguised by their conversational fluency. For example, children of immigrant parents can become proficient in everyday conversation in less than two years. However, it may take a longer period of time for these children to become proficient in literate English. If teachers are not aware of the difference in the time it takes to achieve conversational fluency and proficiency with written English, they might diagnose as learning or reading disabled a conversationally proficient English language learner who has trouble understanding textbooks.
Learning the vocabulary of literate English can be a problem as well for students for whom English is the first language. Words such as renovate, restore, delve, and elude, which might appear in a story from a fifth-grade textbook, are rarely encountered in everyday speech. We cannot assume that children will be familiar with all the words they encounter in school and in textbooks just because they come from English-speaking homes or just because they are proficient in conversational English.
Limitations of the Sources of Information About Words
Learning on their own or as part of a lesson, students have three main sources of information about words: dictionaries, word parts, and context. All of these are important, but each is also problematic.
Dictionaries. Although dictionary use is a main feature of most vocabulary instruction, many students do not receive the kind of instruction they need to learn how to use a dictionary effectively. Traditional instruction in dictionary use focuses on having students look up words and use information from the definitions they find to write sentences. This kind of instruction appears to produce only a superficial understanding and rapid forgetting of a word. Young students often have difficulty interpreting the information in definitions, especially when it comes to how the word is used in a sentence. This is true even when the definitions have been rewritten to make them more user-friendly. In fact, after examining the errors made by students who wrote sentences based on dictionary definitions of new words, the examiners concluded that this activity is "pedagogically useless."
Young students also often have difficulty choosing the appropriate meanings from a dictionary entry for an unknown word. Dictionary definitions that might be accurate for adults are often too convoluted for children to understand, and the simplified definitions found in school dictionaries and glossaries often fail to adequately describe the word's meaning.
Word parts. Students' ability to use word parts — prefixes, suffixes, and roots — to interpret new words can contribute greatly to their vocabulary growth. Nevertheless, word parts are not a completely reliable source of information about word meanings. To illustrate, consider pairs of words such as the following, which share recognizable parts, but which are not clearly related in meaning: casual/casualty, emerge/emergency, sign/resign, sign/design, awe/awful.
Context. Students can acquire a great deal of vocabulary knowledge as they pick up the meanings of words from context as they read widely in appropriately challenging texts. However, the benefits of context are primarily long-term-a matter of gradually accumulating partial information about words as they are encountered repeatedly; the chance of learning the meaning of any particular word from one encounter with that word in context is rather slim.
Finally, to use dictionary definitions, word parts, and context effectively requires awareness of words and flexible thinking-metacognitive and metalinguistic sophistication that many students do not possess. In fact, the students who are most in need of vocabulary growth are likely to be the ones least effective at using these sources of information.
The Complexity of Word Knowledge
What does it mean to know a word? Conventionally, when we talk about knowing a word, we mean knowing its definition. But knowing a word's definition is not the same thing as being able to use that word in speech and writing or to understand a text in which the word appears. People are able to use and to recognize in print words such as at, the, and so, but very few can give a formal definition for them. Definitions are ways we talk about word meanings, but are different from word meanings.
In the conventional form of a definition, the definition first identifies the category to which a word belongs, and then describes how the word differs from other members of that category. A conventional definition of fissure, taken from a widely used dictionary, reads as follows: "a narrow opening [class] produced by cleavage [differentiation]."
The problem with conventional definitions is that they do not always help students to learn word meanings. Indeed, the shortcomings of using such definitions to learn words can be seen in the sentences students write after they have read them. Given the following definition of redress: "set right; repair, remedy," one student wrote the following sentence: "The redress for getting well [when] you're sick is to stay in bed."
Subtle misunderstandings such as this one suggest that for many students, a word's "meaning" is not captured fully in a description of its logical relations to other words. To know a word, students need to encounter it in context and see how its meaning relates to the words around it, and how it relates to the other words that might have been used in its place. They need to understand that worry and fret are ways of showing concern, or that galleon, schooner, and dinghy are all types of boats. In addition, they need to understand how the meaning of words shift and change as they are used in different contexts. For example, look at changes in meaning for the word gave, as it appears in different contexts:
John gave Frank five dollars.
John gave Mary a kiss.
The doctor gave the child an injection.
The orchestra gave a stunning performance.
Although all of these examples involve an act of transmitting, with a giver, a recipient, and something given, each act differs greatly from the others. Students cannot learn this information from a dictionary definition alone. Instead, they need to see the word in many different contexts, to see how the word's meaning changes and shifts.
Adding to the complexity of word knowledge is the fact that all words are not the same. Vocabulary contains function words and content words. Function words are words that have a syntactic function, that are used to alert a reader or speaker to the structure of the sentence. The previous sentence without the words are, that, a, to, or, the, and of reads as follows: Function words have syntactic function, used cue reader speaker structure sentence. Without function words the sentence is unintelligible.
Most speakers of English learn function words readily, in the first stages of language development. There are a relatively small number of such words, with approximately 100 accounting for almost 50 percent of the words used in written English. However, the number of content words is virtually unlimited. Content words are the nouns, verbs, and adjectives that carry information in a text. Content words can be more or less concrete or abstract. Concrete words have a perceptible referent-for example, things, colors, sounds. Abstract words are more difficult to picture, feel, or hear. Not surprisingly, abstract words are more difficult to learn than are concrete words. In vocabulary instruction, the meanings of concrete words can be tied to an object, or shown, whereas the meanings of abstract words have to be taught through examples and non-examples.
Other content words are infrequently used synonyms for words that are already known, such as longevous (long-lived), abattoir (slaughterhouse), and paranomasia (pun). These words may represent different shades of meaning from their synonyms, but knowing the meaning of the more frequent synonym usually gets a reader through a text containing the less frequent word. The reader learns the different shades of meaning though continued exposure.
More often than not, content words represent not just a new term, but a new concept, a new way of organizing ideas and experiences. For example, concepts such as logarithm or photosynthesis need to be learned in the context of other mathematical or biological concepts. We learn concepts through repeated encounters with them in a number of different contexts. Learning word meanings as concepts is vital to vocabulary development-and content-area learning.