Vocabulary: A Review of the Literature, Approaches to Vocabulary Acquisition, and Strategies for Lexical Expansion
Second language or foreign language learners most commonly claim that vocabulary is one of their main weaknesses and that they need to learn vocabulary so that they understand the texts they are reading. While comprehension of language structures such as syntax helps learners understand the relationships between sentences and ideas, it does not provide direct access to the meaning of the sentence. Although teachers do spend time teaching vocabulary, time constraints and coverage of large numbers of vocabulary items are often not possible. Typically, learners’ receptive vocabulary, that is words they recognize but do not use, is larger than their productive vocabulary, words they use when they speak and write. While not every word learners are exposed to needs to become a part of their productive vocabulary, learners to need to expand their vocabulary knowledge base to better understand both academic and literary texts. Although vocabulary teaching is often viewed as being straightforward in that learners simply need sufficient exposure to words, it is a much more complex task than many learners themselves realize. Learning a word means recognizing form (recognizing the word in print and distinguishing the grammatical forms of the word), position (understanding the grammar patterns and structures in which a word can occur), function (knowing the situations and contexts in which the word would most likely occur), and meaning (knowing the various meanings, nuances and subtleties of a word as well as its synonyms). Teachers are continuously faced with the task of deciding which words students need to know, and the most appropriate, effective, and useful ways of teaching those words to their students.
Approaches to Second Language Vocabulary Acquisition
This section describes the main approaches to L2 vocabulary instruction. For an extensive discussion of the studies supporting these approaches readers are encouraged to consult Coady & Huckin 1997; Coxhead, 2000; Coxhead & Nation, 2001; Nation 2001; and Schmitt, 2000. While several main approaches are presented here, it is important to keep in mind that a variety of approaches are often used in the classroom depending on a number of factors including student proficiency level, task or activity, and the purpose of the activity.
Context Studies
One position taken is that students will learn all the vocabulary they need from context alone by simply reading extensively, as long as there is comprehension. Krashen (1989) for example, argues that vocabulary is acquired by reading. He states that students should read large quantities of reading materials that interest them. His main argument is that comprehensible input is what leads to language learning and therefore large amounts of comprehensible input in terms of reading materials will lead to vocabulary acquisition. Research by Nagy, Herman and Anderson (1985) shows that learners do learn large numbers of words by means of incidental learning from written context, but if a learner were to encounter 10,000 unknown words in a given period, he or she might learn 1000–1500 of them. It seems logical then that readers should be taught to use clues in the text to help decipher new words and a blend of direct-definition instruction, and vocabulary learning through context clues can be more effective than one method alone.
Strategy Instruction Studies
The proponents of this view also support the context view of vocabulary acquisition but also emphasize the teaching of specific learning strategies so that students can effectively learn from context. It must be noted that most of these studies have focused on advanced L2 learners who have significant competence in the target language already. Specific vocabulary instruction strategies might include using the key word method (learning new words by learning a keyword “word clue” for each vocabulary word); associating (making associations to other L1 or L2 words or concepts); incidental learning (learning through reading or listening to others read); repeated exposure (using new vocabulary across the curriculum); pre-teaching vocabulary (explicitly teaching word meanings, parts, and usage before reading); restructuring reading materials (substituting an easier synonym for a harder word, summarizing or paraphrasing, or dramatizing a text); and the context method (using clues in the text to help decipher new words). In essence, researchers emphasize that because of the great variation across learners, the teaching of vocabulary learning strategies is essential. Oxford and Crookall (1990) concluded that different vocabulary learning strategies may be appropriate to different students. Other studies have found that direct instruction in a range of strategies including keyword approaches, and metacognitive awareness has led to greater vocabulary acquisition (Altman, 1997; Hulstijn, 1997; Nation, 2001; Oxford & Scarcella, 1994; Parry, 1997). The main position of proponents of this view is that the development of extensive vocabulary knowledge requires some direct instruction and strategy training, as well as extensive reading.
Explicit Vocabulary Instruction
Research in this area has for the most part focused on elementary learners of English and has shown that explicit teaching of certain types of vocabulary using a range of techniques can lead to acquisition. Because the focus has been on the younger learner, there is a greater emphasis on the vocabulary skills needed by students at an earlier stage in their acquisition of the language. Nation (2001) for example, argues that the 2000 most frequent words need to be learned as quickly as possible. Context-specific vocabulary must also be addressed. For example, students using language for academic purposes should be exposed to and should learn academic vocabulary. The University Word List (UWL) first published in 1984 (Xue & Nation) is a list of vocabulary items common in academic texts. It is composed of 808 words, divided into 11 levels. This list is designed to be a list of specialized vocabulary for students who know about 2000 generally common words and plan to study in an English-language college or university. This list has now, however, been replaced by a new word list. Most recently many reading programs have included a component focusing on teaching words from the Academic Word List compiled by Averil Coxhead at Victoria University of Wellington in New Zealand (Coxhead, 1998; 2002). The list was developed from a corpus of approximately 3,500,000 running words of written academic text by examining the range, frequency and uniformity of occurrence of words outside the first 2,000 words of English (West, 1953). This corpus contains four disciplines, which include arts, commerce, law, and science, and each discipline is made up of seven subject areas. The AWL highlights the words which learners will meet in a wide range of academic texts and also provides a useful basis for further research into the nature of academic vocabulary. The division of this word list into smaller sublists helps in the sequencing of teaching and materials, so that a systematic approach to vocabulary learning can be taken. In general, the format would be as follows: Learners would read academic texts and listen to academic lectures and discussions. Where possible, the written and spoken texts would not be too difficult for learners, with no more than about 5% of the running words in the texts being new words for the learners. Learners would also have opportunities to speak in academic discussions and write academic texts using academic vocabulary. Finally, learners would directly study words from the list using word cards and engaging in intensive study of short academic texts (Coxhead & Nation, 2001). In sum, those who include a focused study on vocabulary in such a way would clearly say that a second lexicon can be identified and the effects of knowing them predicted. Furthermore, the goal for L2 readers would be to arrive at a point where 95% of the words are known in an average text which is the point at which independent reading and further acquisition can take place. Other studies have shown that explicit instruction coupled with contextualized reading can lead to greater gains in vocabulary acquisition (Nation, 2001; Paribakht & Wesche, 1997; Zimmerman, 1994).
Classroom Activities
Advocates of this view believe that vocabulary words are best learned through traditional classroom activities, which are often found in practical handbooks for teachers. These books do not advocate any particular methodological approach but offer a variety of activities that teachers can choose from. Beginner level activities, for example, might include communicative activities, picture-matching, and games. Intermediate level activities might include task work, vocabulary learning and recognition strategies, word analysis, simplified readings, and many other vocabulary activities, many of which are described by Singhal (2006). Advanced students might benefit from dictionary work, vocabulary learning strategies, and comprehension work on reading passages varying in content and genre. In short, the basic view here is that teachers can use a number of different kinds of activities and integrate them into the classroom situation when the need arises.
Lexical Problems in Vocabulary Acquisition
The comprehension of text is affected by textually relevant background knowledge and the application of general reading strategies such as predicting the context of the text, guessing unknown words in context, making inferences, recognizing text structure, and so forth. Yet research in both first and second language students has shown that reading comprehension is strongly related to vocabulary knowledge (Coady & Huckin, 1997; Laufer, 1997; Nation, 2001). These studies indicate that an improvement in reading comprehension can be attributed to an increase in vocabulary knowledge and that increased proficiency in high frequency vocabulary also leads to an increase in reading proficiency. Research has also demonstrated that while many L2 readers make use of various reading strategies such as syntactic knowledge and background knowledge, most readers in interpreting texts, tend to regard words as main landmarks of meaning. Background knowledge is relied on to a lesser extent and syntax is almost disregarded. These studies mainly indicated that lexical problems in large part hinder successful comprehension.
Laufer (1997) points out that there are three main lexical problems that may affect reading comprehension which include the problem of insufficient vocabulary, misinterpretations of deceptively transparent words, and the inability to guess unknown words correctly. L2 readers often have difficulty applying reading strategies to texts that they do not understand. For example, if a reader had to determine the main and supporting ideas of a text, it would be difficult to do so unless he or she had a fairly good understanding of the text. On the other hand, identification of text structure might be a simpler task, provided the text had a number of discourse and text markers. For example, a text with such words as “argument,” “supports,” “evidence,” might suggest to the reader that the text is an argumentative one in which the writer makes an argument and then supports it with evidence. However, this strategy itself is of little use if the reader is still unaware of overall meaning and what the specific claims and evidence are. It is, therefore, essential that L2 readers reach a threshold vocabulary. While there is some disagreement over how many words one must know in order to be able to use higher level processing strategies effectively, results of several studies suggest that vocabulary should not be below the minimum of 3,000 word families or 5,000 lexical items.
The second problem affecting reading comprehension is deceptive transparency of words. Words that look familiar will be interpreted to mean what the learner thinks they mean. There are five main types of deceptively transparent words. Figure 1, a summary of Laufer’s (1997) findings, explains and provides an example of each type.
Given the kinds of errors related to deceptive transparency, it is imperative that readers have a better awareness of deceptively transparent words. Doing so will result in a larger number of correctly interpreted words which in turn will enhance text comprehension.
The third major lexical problem that affects reading comprehension is related to the inability to guess words correctly. This occurs when the reader is trying to guess unknown words, those that are unfamiliar to them. Guessing may be possible to some extent but there are a number of factors that interfere with guessing attempts of the reader. Figure 2 summarizes Laufer’s (1997) findings.
Without a doubt, effective reading requires vocabulary knowledge. This is not to say that reading comprehension and vocabulary are one in the same, or that reading quality is determined by vocabulary alone. But while reading strategies are employed by readers to make sense of text, they are of little use if the words of the texts themselves are incomprehensible to the reader.
Methods and Strategies in Vocabulary Teaching
Pre-Reading Vocabulary
Once teachers have selected the text to be used, they need to decide which vocabulary words to teach before students begin to read. This decision is based on what students already know, what they need to know to comprehend the text, and what they will need to know in the future.
Teachers may find it useful to begin by teaching students topic-specific or content-specific vocabulary. For instance, if students will be reading an article on the Internet, it would be useful to present words that might appear frequently in such a text. For example, these words might include website, URL, hypertext, password, search engine, browser, cyberspace, social media, platform and so forth. Working with such vocabulary prior to the reading will enable students to have a general understanding of these words and recognize them when they encounter them in the text.
To present vocabulary before reading, teachers can use exercises presented in textbooks or can create their own activities and exercises. As stated, students can benefit from previewing topic-specific or content-specific vocabulary. By doing so, teachers create the concept or meaning of the word before students are exposed to it in the text. It is crucial therefore that vocabulary is introduced in the context of the topic of the reading text rather than simply a list of vocabulary words that are separate from the topic. This framework of the context enables students to both comprehend and remember words, which in turn facilitates their learning of the word. As Silberstein (1994) points out, the ability to determine the meaning of vocabulary items from context is one of the most important aspects of successful reading. Activities of this type provide practice in inferring meaning from context, which is an important reading skill, and the additional contexts introduced by the teacher provide semantic links that aid readers in remembering items. While vocabulary from context activities are often practiced using reading passages or full discourse context, teachers can create sentence-level activities that ensure students will gain a general sense of the term. Sentence-level items can be taken directly from the text to be read, and teachers can create additional new sentences rich in context. Figure 3 provides some examples.
During Reading Vocabulary
Teachers should emphasize that vocabulary takes time to acquire and that the primary way to expand vocabulary is to read more. The more students read, the more the process will occur naturally. However, as students read, there are specific strategies that should become second nature to them. These include phonics, context, word structure analysis, and dictionary use. Many students have been taught to use phonics or to “sound the word out” in order to determine an unknown word. While phonics often has no connection to actual word meaning, this can still be a good idea in college reading because occasionally hearing the word will trigger something familiar to the student. The next two strategies, context and word structure, both discussed in more detail below, are other strategies students can use to determine meaning. Finally, if that does not work, students should consult a dictionary.
Using Context
The use of context as a strategy is vitally important while students are reading. Guessing the meaning of a word from the other words around it, the context, is perhaps the most useful vocabulary skill that readers can have. The ability to use the words and information around an unknown word in order to guess or infer what that word means in a general sense will serve students well in almost every reading situation. Students should begin by examining the unknown word and determining the part of speech. Looking at the relationship between the clause or sentence containing the unknown word and other sentences or paragraphs can sometimes be very helpful in deciphering word meaning. Sometimes this relationship will be signaled by a conjunction like but, because, if or when, or by an adverb like however, or as a result. Once a guess has been made, substitution of that word within the sentence can usually determine if it is an effective choice. Students can also verify that their guess was the same part of speech.
It is also important that students learn to determine whether or not the meaning of the unknown word is vital both for the purpose for reading the text and for their comprehension of the material in the text. Readers should know that if they can get the overall gist of the text and understand it, they can probably skip over words they are unfamiliar with, provided they are not key words. Various strategies can be modeled so that students learn to distinguish key and non-key words. Teachers in fact can model such strategies while reading. For example, when reading out loud, and when faced with an unfamiliar word, the whole sentence should be read and then the students should be asked whether they understand the overall meaning of the sentence. If not, it is important to determine the meaning of some key words in that sentence. Another strategy is to examine the grammatical function of the word. If it is a function word such as an adverb or adjective, rather than a content word such as a noun or verb, the reader may be able to do without the meaning of the word.
Word Structure Analysis
At the same time students are examining the context of the sentence, they should also look at the different parts of the unfamiliar word to see if there is a word part that they recognize. For example, they may be familiar with what “pre” or “re” mean especially before words like preschool or regain. When faced with less familiar words such as presumption or reexamine, students might recognize that these words are comprised of “pre” and “assumption” and “re” and “examine” respectively. Therefore, use of context in addition to word structure analysis can enable readers to determine word meanings in a given text. Teachers can also spend some time teaching students Latin and Greek stems and affixes that can provide clues to meaning. Charts and tables that students can fill in can be useful exercises because they encourage students to find groups of words containing those stems and affixes which can facilitate the acquisition of words as words can be learned as groupings. It is often the case that words containing these elements are best practiced in their original contexts and teachers simply need to draw students’ attention to the fact that use of both content and word structure analysis can help them identify the meanings of unknown words.
Dictionary Usage
The dictionary plays an important role for college readers; however, most students tend to go to one extreme or the other when using the dictionary. Many students, in an effort to be careful and conscientious, will stop and look up every unfamiliar word they encounter. While for many students this may seem like a good idea, in practice it simply does not work for several reasons. First, it breaks the flow of reading, and it is difficult for the reader to remember what has been read previously. Second, it takes a tremendous amount of time, especially for college students who will encounter new terminology on a regular basis. Finally, this method requires students to have a dictionary with them at all times. Often as a result of encountering the problems just mentioned, students will simply stop consulting the dictionary altogether. Students should learn that the dictionary is a valuable resource after they have already tried to determine the meaning of an unfamiliar word through context and word structure analysis. For instance, there are times when a student might use both of these strategies, and the meaning is still unclear. Other times students may notice several unfamiliar words within the same sentence. Under these circumstances, students should refer to a dictionary for assistance.
Teachers must also spend some time teaching students how to effectively understand the information presented in a dictionary and how to best use their dictionaries. Dictionaries often present a great deal of information but because students are not clear about what this means, they often overlook some very helpful details. Students can benefit from being aware of the following information:
The above information can assist students in using their dictionaries more effectively. There are, however, various other kinds of problems readers may encounter when using a dictionary. Students may have trouble when a form of the word is contained in the definition. For instance, if a student were looking up the meaning of accusation and within its definition found the word accuse, it would then be necessary to take that extra step by looking up accuse. The same is true if the definition contains an unfamiliar word or two. This is one reason it is especially important that teachers assist students in selecting the best dictionary for them — preferably those that also contain example sentences. Numerous apps are now available with this option. Online sites such as Vocabulary.com are also very helpful. Students most frequently complain that they have trouble deciding among the several definitions listed for multiple-meaning words. Once again, teachers must encourage students to revisit the context of the sentence to select the most appropriate meaning for a word.
Post-Reading Vocabulary
It is essential that students revisit vocabulary after the text has been read and discussed. Of course it may be necessary to do some vocabulary work prior to discussion of the text as comprehension and examination of the meaning of the text must come before examination of the language used to convey meaning, but that will depend on the difficulty level of the text itself. Teachers must therefore use their judgment in deciding how and when vocabulary learning will occur once text has been read. Revisiting vocabulary, however, can enhance student comprehension of the text and can promote vocabulary development. Textbooks often include vocabulary exercises both before and after readings often focusing on both recognition and production of words. Some texts include word lists at the back of books with definitions and students should be made aware of such resources. Singhal (2006) presents an extensive list of vocabulary activities. As students become increasingly more proficient in the target language and more independent as learners, teachers can assist them in taking charge of their own vocabulary development. Teaching students a system whereby students can learn and develop their own vocabulary is vital for vocabulary improvement and for helping them become independent readers. Students can be encouraged to dialog with text as they read, noting the meanings of new words in the margins of the texts they are reading or on a separate sheet of paper. Students should be keeping vocabulary logs in which they write the word, write the pronunciation of the word, identify the part of speech of the word, record related family words, copy the dictionary example of the word, write the definition of the word, record any synonyms provided in the dictionary, and finally, write their own sentence using the word. This can be done in a traditional book format, for example in a spiral notebook, or students can carry index cards attached to a metal ring. Regardless of the form the vocabulary log takes, working with a word in such detail provides reinforcement and can lead to actual learning of the word. Students can also revisit words in the text and write paraphrases on the sentences in which those words are used. This kind of activity builds both paraphrasing skills and strengthens word association and use-of-context skills. In sum, no matter how much structure a teacher provides to help students learn vocabulary, ultimately students will have to take the responsibility of developing their own vocabulary. As teachers, we can however, provide them with vocabulary learning strategies they can use throughout their language learning experience.
Extensive Reading and Vocabulary Acquisition
L1 research in vocabulary acquisition has given rise to the incidental vocabulary learning hypothesis which proposes that most vocabulary is learned gradually through repeated exposure in varying contexts. his view holds that on average ten to twelve exposures to the word are necessary over time in order to learn it well. Proponents of this view essentially argue that extensive reading can promote vocabulary growth more than explicit instruction in vocabulary alone. The same views are put forth for L2 learners. Several L2 studies have shown that vocabulary acquisition can improve through extensive reading. The question, however, is how language learners who do not know enough words in the first place to read well, acquire vocabulary. Laufer (1997) points out that a beginner would require knowledge of 3000–5000 word families to achieve even modest comprehension. Coady (1997) provides a preliminary answer to the paradox facing beginning readers. He suggests that the vocabulary acquired through the medium of reading by L2 language learners can be divided into at least three major developmental categories: “those whose forms and common meanings are recognized automatically irrespective of context (or sight vocabulary); those whose forms and meanings are to some degree familiar to the learner but are recognized only in context; and those whose meanings, and often forms, are unknown to the learner and whose meanings must therefore be inferred from the context, looked up in a dictionary, or left uncomprehended” (p. 232). Coady (1997) points out that sight vocabulary consists of medium- to high-frequency words that have been learned through repeated exposure and explicit instruction. Less frequent words will most likely be learned through incidental contact through extensive reading, but only after a critical level of automaticity has been achieved with the high-frequency vocabulary. The implication here is that teachers must assist readers in learning the 3,000 most frequent words so that they become part of their sight vocabulary.
One of the main issues of course is how to get learners to engage in extensive reading. Day and Bamford (2002) suggest that there are many factors, which are interrelated such as not understanding text, reading slowly, not reading much, and not enjoying reading, which can be either causes or effects of one another, constituting the vicious cycle L2 readers are often trapped in. Nuttall (1982) states that one must break the chain in order to move from the vicious circle to the virtuous circle in which one enjoys reading, reads faster, understands better, and reads more. As many proponents of extensive reading would argue, this is best accomplished through pedagogical efforts that emphasize reader interest, theme of text, match between reader’s background knowledge and the text, and the linguistic and cultural authenticity of the text.
Regardless of the methods used, words are essential to language learning. The essential question is how one acquires them. Meaningful experiences and exposure to the target language will certainly lead to increased proficiency. Language acquisition in this case can occur over time through contextual use. If, however, students need to use language for academic tasks and have a limited amount of time in which to acquire these skills, then an instructional or strategy approach will be more beneficial. Moreover, the literature also suggests that systematic vocabulary instruction paired with reading can be a much more successful approach than approaches focusing on learning through context alone or vocabulary instruction alone.
Summary
Vocabulary instruction is an essential element of any reading class as it is vocabulary itself that provides direct access to the meaning of a word. There are numerous approaches to teaching vocabulary which range from emphasizing extensive reading to build word knowledge, strategy instruction which emphasizes the teaching of specific learning strategies so that students can learn from context and use word parts to determine word meanings, to explicit vocabulary instruction, which emphasizes the teaching of word lists, words groups, and academic vocabulary. Research in vocabulary acquisition studies has shown that lexical problems stem from inadequate background knowledge, insufficient vocabulary, misinterpretations of deceptively transparent words where a word may look similar to another word, but differs in meaning, and the inability to apply word identification strategies or the inability to guess unknown words correctly. Pre-reading strategies such as teaching topic-specific or content vocabulary prior to reading texts can help students to better understand concept or meanings before they are exposed to it in the readings. Phonics, context usage, word structure analysis, and dictionary use are the kinds of strategies students should be taught and have an opportunity to practice while reading. Meaningful activities that teach words connected to text topic and content, and activities that encourage the application of vocabulary learning strategies will lead to increased reading proficiency and more skillful readers.
References
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