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1、This document was prepared by the National Center to Improve the Tools of Educators, funded by the U.S. Office of Special Education Programs. Vocabulary Acquisition: Synthesis of the ResearchScott K. BakerDeborah C. SimmonsEdward J. KameenuiUniversity of OregonWe can directly access the meanings of
2、only the words we already know. The referents of new words can be verbally explained only in terms of old words. This can be done either explicitly, by presenting their definitions, or implicitly, by setting them in a context of old words that effectively constrains their meanings. (Adams, 1990, p.
3、205). Introduction The enduring effects of the vocabulary limitations of students with diverse learning needs is becoming increasingly apparent. Nothing less that learning itself depends on language. Certainly, as Adams (1990) suggests, most of our formal education is acquired through language. Lear
4、ning something new does not occur in a vacuum. Rather, new learning always builds on what the learner already knows. Adams suggests that new learning is the process of forming novel combinations of familiar concepts. Learning, as a language-based activity, is fundamentally and profoundly dependent o
5、n vocabulary knowledge. Learners must have access to the meaning of words teachers, or their surrogates (e.g., other adults, books, films, etc.), use to guide them into contemplating known concepts in novel ways (i.e., to learn something new). With inadequate vocabulary knowledge, learners are being
6、 asked to develop novel combinations of known concepts with insufficient tools. Becker (1977) was among the first to highlight the importance of vocabulary development by linking vocabulary size to the academic achievement of disadvantaged students (Baumann & Kameenui, 1991). Thus, he asserted that
7、vocabulary deficiencies were the primary cause of academic failure of disadvantaged students in grades 3 through 12. Almost a decade later, Stanovich (1986) proposed a model of school failure that emphasized the interrelated development of phonological awareness, reading acquisition, and vocabulary
8、growth. Research suggests that students can be taught the phonological awareness skills they need to become proficient readers (Liberman & Liberman, 1990; Stanovich, 1986). In addition, there is empirical support that students who begin school behind typical peers in important areas such as vocabula
9、ry and language development can master basic reading skills as quickly and as well as typical peers under optimal instructional conditions (Carnine, Silbert, & Kameenui, 1990). However, as Becker (1997) observed, the primary difficulty with sustaining early gains in reading is the lack of adequate v
10、ocabulary to meet the broad academic demands that begin in the upper-elementary grades and continue throughout schooling. In contrast to phonological awareness and early reading achievement, no research evidence supports the contention that specific vocabulary development method or program can bridg
11、e the vocabulary gap that exists at the onset of schooling between groups of students with poor versus rich vocabularies, and which continues to widen throughout school and beyond. A flurry of vocabulary research has been conducted since Beckers (1977) observations about the relation between vocabul
12、ary knowledge and academic achievement. Beyond Beckers findings, three additional reasons may account for this renewed interest in vocabulary development. First, because vocabulary and reading are closely related, the highly publicized concern about declining literacy levels, has affected vocabulary
13、 research (Adams, 1990). Second, as Beck and McKeown (1991) observed, the shift to an information-processing orientation in psychology . . . provided rich theory from which to draw in conceiving the relationship between words and ideas (p. 790). Research in vocabulary and literacy demonstrates that
14、building knowledge requires more than accumulating facts about specific elements such as word definitions. Third, related to Beck and McKeowns (1991) comments about building knowledge, is a shift in education from emphasizing basic skills to problem-solving and higher-order thinking skills. This shi
15、ft has resulted in additional research directed toward understanding language and vocabulary acquisition within the context of prior knowledge and constructivist pedagogy. Defining Success in Vocabulary Development It is necessary to distinguish between two contrasting ways of gauging the success of
16、 curricular and instructional programs designed to increase vocabulary development. On one hand, successful programs can be defined in an absolute sense by determining whether they lead to increases in vocabulary beyond what occurs during incidental learning opportunities, or as a result of other ex
17、plicit attempts to increase word knowledge. Alternatively, successful programs can be defined in a relative sense by the extent to which they reduce the well-documented vocabulary gap between students with poor versus rich vocabularies (Stanovich, 1986; White, Graves, & Slater, 1990) . The differenc
18、e between these gauges of success is significant. For example, extensive research evidence supports the use of a number of methods of increasing vocabulary development in an absolute sense (Graves, 1986). However, there is no evidence that any single method or comprehensive program seriously decreas
19、es the vocabulary gap that exists between students with poor vocabularies and those with rich vocabularies. The crucial issue, then, is whether implementation of a program designed to enhance vocabulary development significantly reduces the vocabulary gap between groups of students without restricti
20、ng the vocabulary development of average- and high-achieving students. Organization of Chapter Our goal in this chapter is to identify and discuss areas of recent research on vocabulary development, especially as it relates to diverse learners. In the first part, we describe the methodology of the r
21、esearch review. In the second part, we present five areas of convergence in the research literature on vocabulary acquisition, highlighting issues related to diverse learners. Methodology Sources Our review of vocabulary research included 7 secondary sources, and 16 primary sources. A brief descript
22、ion of the primary sources is listed in Table 1. The principal secondary sources included four book chapters (Anderson & Nagy, 1991; Baumann & Kameenui, 1991; Beck & McKeown, 1991; Kameenui, Dixon, & Carnine, 1987) and three review articles (Graves, 1986; McKeown & Beck, 1988; Paul & ORourke, 1988).
23、 A brief description of these primary and secondary sources is also presented in Table 1. In addition to these seven principal secondary sources, eight sources (Adams, 1990; Becker, 1977; Biemiller, 1977-1978; Carey, 1978; Juel, 1988; Liberman & Liberman, 1990; Nagy & Anderson, 1984; Stanovich, 1986
24、) were used to support important points or provide information not already covered in the secondary sources devoted specifically to vocabulary development. Subject Characteristics The studies reviewed included students identified as general low performers, students with learning or reading disabilit
25、ies, remedial readers not considered to have learning disabilities, high achievers, as well as culturally disadvantaged, language delayed, and linguistically diverse students. Research sources were utilized only if they addressed diverse learners in some way. Diverse learners were defined as those s
26、tudents who by virtue of their instructional, experiential, cognitive, socioeconomic, linguistic, and physiological backgrounds bring different and often additional requirements to traditional instruction and curriculum. Summarization of Methodology Two independent reviewers read and coded each prim
27、ary and secondary source, except the Graves (1986) and Kameenui et al. (1987) chapters which were read and coded by one reviewer because they were not included in the initial vocabulary search. All references were coded on three dimensions: (a) general conclusions, (b) learner characteristics, and (
28、c) instructional implications. Convergence within the dimensions was achieved through a multiple-step process. Reliability was attained by combining independent reviews, inter-coder comparisons of data categorization, coding clarification, and refinement with reliability checks on all sources. To de
29、rive general areas of convergence, the primary author of this chapter used the convergent responses from the review and coding process in concert with a second examination of each source. Other chapters in this research synthesis have included separate sections on findings and implications for skill
30、ed and diverse learners. This pattern was difficult to follow with the research on vocabulary acquisition. Our understanding of the outcomes of vocabulary acquisition clearly surpasses our understanding of the process of vocabulary acquisition. However, the early indication is that the acquisition p
31、rocess is similar for all students regardless of vocabulary knowledge. Consequently, it may be more useful to discuss differences in word knowledge as differences on a continuum rather than as different processes that distinguish students with poor from students with rich vocabularies. In addition,
32、studies that theorize about the process of vocabulary acquisition compare and contrast students with poor versus rich vocabularies in the same sections. Therefore, we will follow this strategy as much as possible in this synthesis. Areas of Convergence In examining the research evidence on vocabular
33、y acquisition, five themes emerged and converged. These themes addressed (a) vocabulary size differences between students, (b) accounting for those differences theoretically, (c) successful methods to improve the vocabularies of students with diverse learning needs, and (d) the relation between voca
34、bulary knowledge and reading achievement. The Vocabulary Gap Between Groups of Students The first area of convergence is that vocabulary differences between students are extensive. In this section, we present evidence that the difference in the number of words known by students with poor vocabularie
35、s versus students with rich vocabularies is extensive, grows over time, and becomes apparent early. Vocabulary Size In their review of vocabulary acquisition, Beck and McKeown (1991) noted that estimating vocabulary size was probably the oldest type of vocabulary research. Thus, during the 20th cent
36、ury, scores of studies have focused exclusively on estimating vocabulary size. Given the complexity of defining word knowledge (Baumann & Kameenui, 1991), it is not surprising that such estimates have varied considerably. For example, Graves (1986) reported that studies of vocabulary size conducted
37、prior to 1960 resulted in estimates ranging from 2,500 to 26,000 words for typical first-grade students, and from about 19,000 to 200,000 words for university graduate students. These discrepancies were due to lack of specificity regarding (a) differences between words and word families (e.g., is a
38、student who knows the meaning of run , ran , and running credited with knowing one, two, or three words?); (b) definitions of word knowledge (e.g., recognizing the meaning of a word in a multiple-choice question versus producing a definition for the word); and (c) the source used to represent Englis
39、h vocabulary (e.g., dictionaries versus word frequency lists) (Beck & McKeown, 1991). As researchers began to specify more precisely the parameters of vocabulary knowledge, more accurate and consistent estimates of vocabulary size were generated. For example, Nagy and Anderson (1984) attempted to de
40、termine the number of printed words used in English materials in grades 3 through 9 by examining the textbooks, workbooks, novels, magazines, and encyclopedias used in the classroom. Their estimate of 88,533 word families is now widely used as the domain of words that students in grades 3 through 9
41、can be expected to know. Beck and McKeown (1991) provided another estimate of the number of words students know by examining recent studies that used more defined criteria following the tradition established by Nagy and Anderson (1984). Through more precise measures, for example, estimates of the vo
42、cabulary size for 5- to 6-year-olds dropped from a range of between 2,500 to 26,000 words to between 2,500 to 5,000 words. In summary, estimates of vocabulary size have become more consistent during the last 10 years. Methodological procedures that have helped reduce past variances include (a) defin
43、ing more precisely the domain of words being drawn upon to assess knowledge and (b) considering the difference between words and word families when calculating estimates. Vocabulary Growth Closely related to vocabulary size is vocabulary growth, or the number of new words students learn each year. N
44、ot surprisingly, the methodological problems that have plagued estimates of vocabulary size have also plagued estimates of growth. Thus, estimates of vocabulary growth have varied widely. For instance, early research on vocabulary growth resulted in estimates that students learned as few as 1,000 wo
45、rds to as many as 7,300 new words per year (Beck & McKeown, 1991). As definitions of vocabulary knowledge have become more refined, estimates of growth have become more consistent. For example, three widely cited reviews of vocabulary research suggest that the number of new words students learn, esp
46、ecially in the primary grades, is about 3,000 new words per year (Baumann & Kameenui, 1991; Beck and McKeown, 1991; Graves, 1986). Students who learn the meaning of 3,000 words per year must learn approximately 8 words per day. This incredible growth may be due in part to neurological makeup, in whi
47、ch children act as spontaneous apprentices in the business of language, acquiring new words at such a phenomenal rate (Miller, cited in Liberman & Liberman, 1990, p. 58). In addition, such high growth rates can be accomplished only if flexible definitions of word knowledge and learning are used. In
48、discussing vocabulary knowledge, Carey (1978) distinguished between fast mapping and extended mapping. In fast mapping, an individual is able to learn a very cursory meaning of a word quickly, sometimes after just one exposure. It is not until extended mapping occurs, however, that an individual gai
49、ns full understanding of a words meaning. To attain extended mapping sometimes takes years and multiple exposures to a word. Carey hypothesized that school-aged children may be working on as many as 1,600 word mappings simultaneously. That is, at any point in time as many as 1,600 words are at various stages of mapping. So, if a student learns the meaning of eight new vocabulary words per day, the majority of those words are learned at only a very basic level of understanding. Vocabulary Differences
