Summary
This article presents an empirical study that investigates the role of vocabulary knowledge in listening comprehension with 115 advanced Danish learners of English as a foreign language (EFL). The dimensions of depth and breadth of vocabulary knowledge (measured by the Vocabulary Levels test and the Word Associates Test) were found to be significantly correlated with listening comprehension (measured by a listening test from the Cambridge certificate of proficiency in English) and could predict half of the variance in the listening scores. This study thus provides empirical evidence that vocabulary knowledge is an important factor for successful listening comprehension in EFL. This study reports on such an investigation that explored the contribution of depth and breadth of vocabulary knowledge to advanced L2 learners’ listening comprehension in English.
Although a considerable number of studies have found vocabulary knowledge to be a significant determinant of reading success in the L2 and have established specific vocabulary size and lexical coverage targets for adequate comprehension (e.g., Hazenberg & Hulstjin, 1996; search has addressed such issues with regard to listening (e.g., Bonk, 2000). The present study is thus motivated by a lack of empirical research on the role of vocabulary knowledge in listening comprehension and by the ensuing need to explore the extent to which different dimensions of learners’ vocabulary knowledge will contribute to L2 learners’ listening success.
Theoretical Background
Breadth of vocabulary knowledge is defined as the size of a learner’s vocabulary-that it, the number of words for which the learner has at least some knowledge of meaning. Meara (1996a) argued that vocabulary size is the basic dimension of a learner’s lexical competence and emphasized that learners with large vocabularies are more proficient language users than learners with smaller vocabularies. In contrast, depth of vocabulary knowledge is defined as the quality of lexical knowledge that reflects how well a learner knows individual words or how well words are organized in the learner’s mental lexicon. The present study addresses vocabulary knowledge from the dimensions of breadth and depth in the vocabulary and operationalizes depth of vocabulary knowledge as the score on a modified version of the Word Associates Test.
In light of the fact that word recognition is a prerequisites for spoken language comprehension, it may be hypothesized that learners; knowledge of words will be strongly associated with their listening success. However, knowledge of a word is no guarantee that the word will actually be recognized in continuous speech. Moreover, recognizing most of the words in the input does not guarantee comprehension, as many other factors also affect L2 listening comprehension.
In general, studies have found significant correlations between vocabulary size and reading comprehension tests in the range from .50 to .85 for EFL learners from different proficiency levels (e.g., Henriksen, Albrechtsen, &Haastrup, 2004; Laufer, 1992; Qian, 1999, 2002; Staehr, 2008). Although theresults from these studies emphasize that vocabulary knowledge is a determining factor for reading success, such findings simply cannot be transferred to listening; that is, it cannot be assumed that vocabulary knowledge plays an equally significant role and that identical vocabulary size or lexical coverage thresholds will apply to listening comprehension.
The notion that there is a difference between the role of vocabulary in reading and in listening is suggested by Mecartty (2000), who found lexical knowledge to be more highly correlated with reading than with listening in a study of Spanish as a L2. Bonk (2000) investigated the relationship between vocabulary knowledge and listening comprehension in EFL but attempted to determine a lexical coverage threshold which it would be impossible for learners to achieve good listening comprehension. The results indicate that the relationship between vocabulary knowledge and listening comprehension is complex and by no means an unequivocal one and that further investigation into threshold of lexical coverage and vocabulary size for adequate listening comprehension is necessary.
Research Questions
The study was designed to address the following research questions:
- To what extent are vocabulary size and depth of vocabulary knowledge associated with listening comprehension?
- To what extent does depth of vocabulary knowledge, in addition to vocabulary size, contribute to successful listening comprehension?
- How much vocabulary is needed for adequate listening comprehension?
Method
Participants
The study comprised 115 Danish EFL learners (90 female and 25 male) who were first year students of English at the Copenhagen Business School.
Instruments
The participants were given three paper-and-pencil tests; a listening comprehension test, a vocabulary size test, and a depth of vocabulary knowledge test. Listening comprehension test was used to assess the participants’ listening comprehension, a standardized listening test from the Cambridge certificate of proficiency in English (CPE) (2002). Vocabulary levels test was used to assess the learners’ vocabulary size or breadth of vocabulary knowledge. The depth of vocabulary test was specifically developed in a format similar to the World Associates Test (Read, 1993, 1998).
Procedure
The three tests were administered to the participants in one session.
Result
It is worth noting that the listening comprehension test appears to have an appropriate level of difficulty for the participants but that it displays a relatively low reliability coefficient. Given the fact that the listening comprehension test is a standardized test administered according to the guidelines provided by Cambridge ESOL, this degree of reliability may seem rather surprising. However, one reason for this low alpha coefficient might be that the group of participants was very homogenous and did not produce mush variance in the listening scores, which would contribute to a deflation of the reliability estimate.
The results of the study show that larger vocabulary size and more lexical coverage will lead to better comprehension and suggest that the relationship between the two is linear. Listening comprehension increases from 54% at the 90% coverage level (or 2000 vocabulary size level) to 80% at the 99% coverage level (or 10.000 vocabulary size level), which represents an increase of 26 percentage points. It is worth noting in particular that the results show a greater increase in comprehension from 94% to 98% lexical coverage (i.e., from the 3.000 to the 5.000 vocabulary level) than from 90% to 94% lexical coverage (i.e., from the 2000 to the 3000 vocabulary level). This significant change in comprehension is not dramatic enough to suggest a vocabulary threshold, but it indicates that receptive knowledge of the most frequent 5.000 word families, which results in a lexical coverage of 98%, led participants to significantly better comprehension.
Given this fact, the results of the present study tentatively suggest that 5.000 word families might be a useful vocabulary size target for advanced foreign language listeners. However, the degree of lexical coverage required and the vocabulary size needed to reach this coverage will always depend on the input text and the degree of comprehension required.
Comment
The present study reports such an investigation that explored the contribution of depth and breadth of vocabulary knowledge to advanced L2 learners’ listening comprehension in English. The study is motivated by a lack of empirical research on the role of vocabulary knowledge in listening comprehension and by the ensuing need to explore the extent to which different dimensions of learner’s vocabulary knowledge will contribute to L2 learners’ listening success.
The results showed that depth and breadth of vocabulary knowledge were highly correlated with listening comprehension and together predicted half of the variance in the listening scores. This significant contribution indicates that these dimensions are important factors for successful listening comprehension in English.
These results tentatively suggest that receptive vocabulary knowledge is almost as important for listening as it is for reading, although stronger relationships have been found between vocabulary size and reading tests.
Vocabulary Level Test was used to measure knowledge of the written form of the word, whereas listening involves recognizing the spoken form of the word. This might constitute a potential problem given the fact that a word recognized in its written form will not necessarily also be recognized in its spoken form.
It is argued that a study of the relationship between vocabulary size and listening should be based on a vocabulary test that involves hearing the target words rather than reading them. However, when this study was carried out, no suitable test of phonological vocabulary size existed that could be used with fairly advanced learners of English. Furthermore, it was decided to use a standardized measure of vocabulary size that was comparable to other vocabulary studies.
It is hypothesized that the written form of the words could had a depressing effect on the correlation between vocabulary size and listening comprehension and that if the study had involved a test of phonological vocabulary size, it might have produced an even higher correlation.
Overall, the present study found that larger vocabulary size and more lexica coverage will lead to a higher degree of comprehension. The question is, however, what in fact constitutes adequate or acceptable listening comprehension? It is obviously impossible to define a generic cutoff score for adequate comprehension in a listening or reading test, but it might be useful to briefly consider earlier studies by Laufer (19890 and Hazenberg and Hulstijn (1996), who attempted to determine minimal vocabulary size or lexica coverage requirements for adequate reading comprehension. Laufer set the cutoff point for reasonable comprehension at 55% in reading comprehension test. In comparison, the hazenberg and Hulstjin study defined the criterion for acceptable for acceptable reading comprehension as the pass or fail cutoff of a minimum 70% to pass in a reading test.
The findings of the study indicate that a vocabulary size of 5.000 word families might be an important learning goal for advanced learners of English. It is somewhat larger than the estimates for reading suggested by Laufer (1992) and Hirsh and Nation (1992), which indicates that more vocabulary is needed for text comprehension than previously thought. However, it needs to be recognized that different criteria for adequate comprehension were applied. Nation (2006) calculated that a vocabulary of 8.000-9.000 word families is needed for comprehension of written text, whereas a vocabulary of 6.000-7.000 word families is needed for spoken test. These estimates for coping with spoken text appear to be more similar to the results of the present study.
The present study crucially found that a vocabulary size of 5.000 word families led to a lexica coverage of 98% in the input texts. Given the fact that the 5.000 word level might be a good indicator of adequate comprehension, this is a very interesting result, as it clearly reinforces Hu and Nation’s (2000) findings that text coverage of 98% will be needed by most learners to achieve adequate comprehension. Their results were obtained in relation to reading, but Nation argued that a coverage figure like this might also apply to listening. The results from the present study indicate that text coverage of 98% might in fact be a sufficient coverage for dealing with spoken texts.
Apart from the findings on vocabulary size and lexical coverage, the data of the current study revealed that depth of vocabulary knowledge, operationalized through a word associates test, correlated significantly with listening comprehension and could contribute significantly to the prediction of the listening scores. There may be several potential reasons as to why depth of vocabulary knowledge-in addition to breadth- did not make a more substantial contribution.
On one hand, it might be argued that the vocabulary size and depth of vocabulary knowledge measures may have tapped into the same dimensions of vocabulary knowledge because both targeted knowledge of word meaning and thereby created a partial construct overlap. On the other hand, it might also be argued that the two tests were in fact different enough to measure different constructs because the depth of vocabulary knowledge test also testes knowledge of different meanings for the same word as well as knowledge of collocations. The high correlation between the two measures does not necessarily mean that the two constructs are identical but may simply reflect the fact that the development of depth and breadth of vocabulary knowledge is somewhat interdependent and that a person who knows many words is also likely to know much about each word.
Because the participants of the current study were advanced EFL learners, this may explain why the results revealed a high correlation between their breadth and depth of vocabulary knowledge and may partly explain why depth, in addition to breadth, could only predict very little of the variance in the listening scores. However, it is worth noting that Qian (1999, 2002), using similar vocabulary measures, found that depth, in addition to vocabulary size, could contribute significantly and rather substantially to the prediction of reading scores, despite a high correlation between the two dimensions of vocabulary. This finding might suggest that, if the relationship between vocabulary depth and listening had been strong enough, depth, in addition to vocabulary size, would also have contributed substantially to the variance in the listening scores.
The findings of the current study tentatively suggest that vocabulary size is the basic component in listening and do not seem to support the hypothesis that depth of vocabulary knowledge, in addition to vocabulary size, can pay a separate role in listening. However, the results similarly indicate that, to uncover the role of depth in listening, more research is needed on the relationship between breadth and depth of vocabulary knowledge and such investigations should take into account different conceptualizations of depth.
The present study has provided empirical evidence of a strong association between L2 learners’ vocabulary knowledge and their listening comprehension, and the findings suggest that vocabulary size might be a major contributing factor to successful listening comprehension.
The results presented here have direct implications for language teaching. The findings draw attention to the need for an explicit focus on expanding learners’ vocabulary size in the 2 classroom, to enable them to reach a lexical coverage of the input texts of around 98%.
However, although this study has found vocabulary knowledge to be an important factor for listening success in EFL by showing that it can explain half of the variance in the listening scores, it must also be acknowledged that a range of other linguistic and nonlinguistic factors contribute to L2 listening success. In addition to an explicit focus on vocabulary learning, it might be useful to teach receptive compensation strategies in the L2 classroom as part of developing learners’ strategic competence.
Written by : Erlyna A.
Student of Islamic University of Malang, Graduate Program
Written by : Erlyna A.
Student of Islamic University of Malang, Graduate Program