Literacy

How does one help students learn vocabulary? Solutions take two general directions: one focuses on learning word meanings from context through wide reading and the other on the need for direct instruction about word meanings.

What Is Known and How to Know It

The divergent recommendations of wide reading versus direct instruction derive from different assumptions about the extent of vocabulary knowledge, that is, how many words children typically know, and how readily new words are learned. For example, rapid word learning and large vocabularies would indicate a lesser role for instruction, while slower growth would indicate need for intervention.

Vocabulary size and growth. A key issue is that estimates of vocabulary size vary widely. For example, estimates of total vocabulary size for first graders have ranged from about 2,500 (Edward Dolch and Madorah E. Smith) to about 25,000 (Burleigh Shibles and Mary Katherine Smith), and for college students from 19,000 (Edwin Doran and Edwin Kirkpatrick) to 200,000 (George Hartmann).

Situations with such wide variations make it impossible to simply ask people how many words they know, so estimates must be based on testing people's word knowledge of a sample of words and extrapolating to a final figure. To construct such tests, decisions must be made about what is taken as evidence of knowledge of a word, what constitutes a single word (e.g., should individuals who know the word walk be credited with knowing the word walking?), and how a sample of words is chosen to represent the language. All these decisions open the door to wide discrepancies in vocabulary size estimations.

Work on what constitutes a word and on techniques for constructing a language sample have helped bring estimates into greater agreement. Consequently, estimates in the early twenty-first century place vocabulary size for five-to six-year-olds at between 2,500 and 5,000 words. But although the problems of older work on vocabulary size are understood, there are (as of 2001) no recent, large-scale studies that correct these problems.

Estimates of vocabulary size at different ages are also used to estimate rates of vocabulary growth. Specific estimates of vocabulary growth, not surprisingly, vary widely, from three (Martin Joos) to twenty new words per day (George Miller). A figure of seven words per day is probably the most commonly cited.

Whatever the reality, it is certain that there are wide individual differences in both vocabulary size and growth. Studies have found profound differences among learners from different ability or socioeconomic groups, from toddlers through high school. For example, Mary Katherine Smith reported that high-knowledge third graders had vocabularies about equal to lowest-performing twelfth graders. These differences, once established, appear difficult to ameliorate. This is because children whose backgrounds provide rich verbal environments not only learn more words initially, but they also acquire understanding about language that enables them to continue to learn words more readily.

Learning from context. Most word meanings are learned from context. This is true from the earliest stages of a child's language acquisition onward, but the type of context changes. Early learning takes place through oral context, while later vocabulary learning shifts to written context. Written context lacks many of the features of oral language that support learning new word meanings, features such as intonation, body language, and shared physical surroundings. Thus, written context is a less efficient vehicle for learning. Research shows that learning from written context occurs, but in small increments. Machteld Swanborn and Kees de Glopper estimate that of one hundred unfamiliar words met in reading, between three and eight will be learned. Thus, students could substantially increase vocabulary if two conditions are met. First, students must read widely enough to encounter a substantial number of unfamiliar words. Second, students must have the skills to infer word-meaning information from the contexts they read. The problem is that many students in need of vocabulary development do not engage in wide reading, especially of the kinds of books that contain unfamiliar vocabulary, and these students are less able to derive meaningful information from context. So depending on wide reading as a source of vocabulary growth could leave some students behind.

Direct instruction. The most commonly cited problem with direct instruction to address students' vocabulary needs is that there are too many words to teach. This is certainly true if the goal is to teach all the words in a language. Consider, however, a mature vocabulary as comprising three tiers. The first tier consists of basic words–mother, ball, go–that rarely require instructional attention. The third tier contains words of low frequency that are typically limited to specific domains–isotope, peninsula, refinery. These words are appropriate for specific needs, such as introducing the word peninsula during a geography lesson. The second tier contains high frequency, general words, such as compromise, extraordinary, and typical. Because of the large role tier-two words play in a language user's repertoire, instruction directed toward these could be valuable in contributing to vocabulary growth.

What kind of instruction should be offered? The answer depends on the goal. Typically, educators want students to know words well enough to facilitate reading comprehension and to use the words in their own speech and writing. Facilitating comprehension seems a reasonable goal, given the well-established relationship between vocabulary knowledge and comprehension. Although virtually all studies that present vocabulary instruction result in students learning words, few have succeeded in improving comprehension. In analyzing this discrepancy, researchers, such as Steven Stahl and Marilyn Fairbanks, found that to influence comprehension instruction needs to: (1) present multiple exposures of words; (2) involve a breadth of information, beyond definitions; (3) engage active processing by getting students to think about and interact with words.

Effective instruction should accomplish the following:

• Begin with information about the word's meaning, but not necessarily a formal definition.
• Immediately prompt students to use the word.
• Keep bringing the words back in a variety of formal and informal ways.
• Get students to take their word learning beyond the classroom.
• Help students use context productively.

Status of Vocabulary Issues

Although there is general consensus on effective vocabulary instruction, little of this kind of instruction is found in classrooms. Attention to vocabulary in classrooms focuses on looking up definitions and perhaps writing sentences for new words. The typical dictionary definitions, however, do not promote students' learning of new word meanings. In fact, often students do not even understand the definitions of the words they look up. Thus it is important to implement what is known about effective instruction into classrooms.

Much about the way vocabulary is learned and stored in memory is still unknown. How much learning comes from oral contexts past initial stages of acquisition? How much do early learning experiences matter and is it possible for children who lag early to catch up? What characteristics of verbal environments are most useful for word learning? For example, what are the roles of the amount of talk in a child's environment, the kinds of words used, and interactions within the environment? How is word knowledge organized? Research makes it clear that a person's vocabulary knowledge does not exist as a stored list of words, but rather as networks of relationships. This leads to the question, how do these networks of word relationships affect how readily and how well words are learned?

To help students improve their vocabulary, it will be necessary to put into practice what is already known about vocabulary learning and evaluate and refine the results.