论文总字数：45871字

摘 要

词汇是语言的核心，因而获取词汇知识对典型的语言学者而言至关重要。近年来，大量学者开始研究二语习得中的焦点——二语学习者的词汇习得。他们主要基于两个理论基础：投入量假设和输入输出假设，大多研究任务类型对词汇习得的影响，在词汇习得的层面以接受性词义和产出性词义为主。前期文献大都证实了投入量假设和输入输出假设的正确性，但是研究中仍存在很多问题亟待解决，因而研究结果存在片面性。本研究以修改版的词汇知识量表测量为衡量标准，总结前期文献，探究不同词汇学习任务任务对目标词熟悉程度的影响。

具体而言，本实证研究解决此问题：

二语词汇学习任务是否影响词汇习得？

本研究采用单向被试间设计，其中任务类型作自变量，而目标词的熟悉程度则为因变量。在这项研究中，任务类型被分为三个层次，分别为：词意匹配，组合句子，根据释义写目标词。其中词意匹配被认为输入，而组合句子和写单词则被认为是输出。在一项科学实验中，因变量依赖于自变量并随自变量的改变而改变。

本次试验的主体是来自南京工业大学两个自然班的75名非英语专业大学二年级学生，其中20名来自工管，20名来自通信工程，35名来自药学专业。所有受试者为学习英语八年的中国人，他们同意遵循指示并加以配合。为了探索研究问题，他们被随机分配到三个大小相等的组。随机分配保证每个参与者处在每一组的概率相同。他们读取三组相同的句子，其中每组包含6句。随后，去完成以独立的目标词为基础的任务。实验研究人员采用单一方差分析解决研究问题。

本实验研究结果显示：词汇学习任务对二语学习者的词汇习得影响显著。具体而言，词意匹配和组合句子对二语学习者的词汇习得没有显著影响 (p gt; .05)，但写目标词那组则影响显著，比其余两组都表现甚好(p lt; .05)。这一结果支持了接受性二语习得词汇知识方面的输入输出假设。研究结果支持Swain（1993）的观点，输出活动引起的二语学习者对语言形式的反思，这使得词汇习得更可能发生。这似乎是合理的，通过建立强大的形意连接，输出活动实现了目标词的深加工。

此研究对理论构建有一定贡献,揭示出二语词汇知识习得领域输出活动相对于任务输入的优势，同时也为二语教师提供了更好的词汇知识教学方法。

关键词: 输入输出假设 词汇学习任务 词汇习得

1.Introduction

The present study intends to summarize the early literature on vocabulary acquisition and explore the effect of vocabulary learning task on vocabulary acquisition. Specifically speaking, this chapter will provide the background and purposes of the research.

1.1 Background of the study

The past decade has witnessed the second language vocabulary acquisition (SLVA) research scope’s expansion in China. Vocabulary contributing greatly to listening, speaking, reading and writing skills, therefore is the core of language and is of vital importance to typical language learners to acquire vocabulary knowledge. According to D.A. Wilkins(1972), without grammar, communication may still proceed, but without vocabulary, communication will probably break down. So vocabulary attaches great importance to the second language acquisition and SLVA is a complicated combination of input and output which accompanies the second language learners’ lifetime.

In recent years, task-based L2 vocabulary acquisition has come to the forefront. L2 vocabulary task has different levels, which can achieve different vocabulary learning goals by designing different learning activities. Motivated by the assumption that some tasks may perform better than others, a great number of scholars have begun to study L2 learners’ vocabulary acquisition under different kinds of task types. Based on the input-output hypothesis and involvement load hypothesis, most of those early studies have confirmed the correctness of input-output hypothesis and the involvement load hypothesis. However, for most differences between input and output can be measured by the degrees of involvement load, most of previous researches emphasize involvement load hypothesis rather than input-output hypothesis, which lead to some problems in previous studies. So, it may be better to respectively investigate the effects of task type(input and output) and involvement load.

In addition, during the second language’s teaching process, teachers usually pay more attention to vocabulary learning since L2 vocabulary is one of the main goals in the course syllabus. They have tried many ways to help students’ vocabulary acquisition, such as: audio-visual method, meaning match, and task-oriented approach to create the contexts facilitating word learning. What’s more, in order to meet the need of communication, EFL learners also spare no effort to grasp new words. By way of helping L2 teachers and learners find the effective ways to acquire new words, SLVA scholars both at home and abroad have carried out numerous theoretical descriptions and empirical studies, which mainly at the aspects of vocabulary incidental acquisition and learner’s vocabulary learning strategies and most of them lack familiarity with the vocabulary meaning, which lead to many issues remain unsolved.

1.2 Purposes of the study

Given the above limitations in the previous researches, this study is designed to continue this line of research, enrich the theory frameworks and explore the effect of vocabulary learning task type on vocabulary acquisition. The present study also has realistic purposes: we hope to find a practical way to facilitate L2 learners’ vocabulary acquisition, to help L2 teachers’ vocabulary teaching and to promote researchers’ material design.

Literature review

This chapter mainly deals with the involvement load hypothesis and input-output Hypothesis. At the same time, it also reviews the previous studies and their limitations in the second language acquisition.

2.1 The Involvement Load Hypothesis

The involvement load hypothesis was developed from Craik and Lockhart’s (1972) processing depth theory and was put up by Laufer and Husting’s in 2001. It states that despite of task type (input or output), a task with higher degrees of need, search, and evaluation induces a higher involvement load, and therefore is thought to be more effective than those with a lower involvement load for incidental L2 vocabulary learning.

The involvement load hypothesis suggests that memory trace is the by-product of perceptual analysis of a stimulus and the trace is mainly determined by the depth at which that word is processed. In 2001, Hulstijn amp; Laufer put that the amount of motivational-cognitive involvement is an ope-rationalizable definition of the depth of processing and elaboration in incidental L2 vocabulary recall and retention. Taking reading tasks for example, this theory supports that the second language vocabulary acquisition in reading has something to do with reading tasks and it believes that different tasks can cause different learning effects by varying degrees of cognitive processing. The task-induced involvement load hypothesis consists of three basic components: need, search and evaluation. According to task requirements, the “need” component is the motivation and can be divided into two degrees: moderate degree(1) when it is imposed externally or strong degree (2) when it is imposed internally. The “search” component is defined as cognitive component, it happens when one attempts to find the meaning of an unknown word in a dictionary or from his teachers. What’s more, “evaluation” is a cognitive dimension of involvement which refers to a process of comparison. It happens in three levels: the word is not compared with other words(0); comparison of a given word with others or a specific meaning of a word in the provided context (1); Comparison of a given word with others or a specific meaning of a word in an original context(2).

According to Hulstijn and Laufer (2001), the involvement load of a given task can be defined as the involvement index in which the absence of a component is marked 0, a moderate presence 1, and a strong presence 2. This kind of definition combined “attention”, “elaboration” with “depth of processing” into a concrete task-specific construct. The Involvement Load Hypothesis points that the higher the level (need, search, and evaluation)of the involvement load, the more effective the task is in the second language vocabulary acquisition.

2.2 The input-output hypothesis and L2 vocabulary acquisition

The input hypothesis is developed by linguist Stephen Krashen in 1980s, which attaches great importance to comprehensible input and is widely accepted at that time by scholars in SLA field. According to Krashen (1989), adequate comprehensive input is the only one necessary and sufficient condition for SLA acquisition. Only in that way language learners can notice the input, among which “i 1” theory is well received. “i 1” theory states that we acquire something only when we understand language that contains structure that is little beyond where we are know. That is to say L2 input that is one step higher than their exiting stage of linguistic competence, SLA can take place and they can improve a lot and have a big progress. He pays much attention to input hypothesis but ignores output hypothesis.

L2 output can improve L2 learners’ noticing, since it is a mental process, which will lead L2 learners to notice their deficiencies and to verify their production. The comprehensible output hypothesis states that we acquire a language when we attempt to transmit a message but fail and have to try again. Eventually, we arrive at the correct form of our utterance, our conversational partner finally understands, and we acquire the new form we have produced. According to Swain’s comprehensible output hypothesis (1995), output is not only the result but also the cause of L2 vocabulary acquisition. Admittedly, output production has a deeper processing of the L2 words so it can help L2 learners better acquire the words. Also,by internal or external feedback, output enables them to notice a gap in their existing knowledge, which will be the cause and motivation of the language. To sum up, input or output alone is not sufficient in SLA. Only by combining the two together, can we receive a good result in the process of learning a language.

2.3 The previous studies and limitations in SLA

The British linguist D.A.Wilkins said: “without grammar, people cannot express many things; without vocabulary, people are unable to express anything.” Language includes listening, speaking, reading and writing. Each language skills can’t do without vocabulary support and the second language vocabulary acquisition is a process comparing ones lifetime. So vocabulary acquisition has long been the center in the field of SLA. Scholars both from home and abroad have carried out theory and empirical researches on the second language vocabulary acquisition from different aspects. At present, researches in second language vocabulary acquisition mainly focus on learning tasks, incidental vocabulary acquisition and language learners' vocabulary learning strategies.

Most previous researches focused on the involvement load hypothesis instead of input-output hypothesis, partly because most distinctions between L2 input and output might be indicated by different degrees of involvement load. However, different types of both input and output could induce different degrees of involvement load. It might be interesting to separate task types (input and output) from involvement load to investigate the respective effects of task type and involvement load.

What’s more, the number of target words used in most previous researches were limited to about ten words, which might make the measures of L2 vocabulary acquisition inaccurate.

Finally, although a number of studies used randomized experiments, the majority of the studies used non-randomized experiments, rendering a comparison of the results from different studies difficult.

Given these limitations in the previous research, this study was a continuation of this line of research, but attempted to improve the research design to investigate the relative contributions of the input-out hypothesis and the involvement. In order to improve the reliability of L2 vocabulary acquisition measures, the target words would be increased to as many as 18 words. In addition, a true experiment was to be conducted, where random assignment of subjects to each L2 vocabulary learning task was made, in the hope of improving the internal validity of the research. The input and output orientation of L2 vocabulary learning task were to be internationalized as commonly found in typical L2 classrooms so that the external validity might be improved.

2.3.1 Earlier studies about vocabulary learning tasks on vocabulary acquisition

When learners learn words through various activities such as reading texts, solving reading comprehension tasks, making sentences, and semantic match, etc, their attention is concentrated on some other features rather than the vocabulary itself, it is incidental vocabulary learning. Different learning tasks, including input and output, may have different effects on second language acquisition. Hulstijn (1992) found that word retention was better when L2 learners chose the meaning of target words in a text from several synonyms compared to when the word meaning was explained by a synonym. Hulstijn and Trompetter (1998) made a reading group and a composition group, and the result showed that the composition group was more successful than the reading alone group in vocabulary gains test. “Based on theory of Involvement Load Hypothesis, it is proved that compared with tasks of little involvement Load, “heavy involvement Load can help EFL learners remember target words better” (Zhou Hao, 2006, p.66).

2.3.2 Limitations on the previous studies in the field of SLA

From the above review, it can be concluded that all the above empirical studies are valuable in demonstrating the roles of different factors in incidental vocabulary acquisition through reading. Moreover, they provoke a perspective to analyze the issue from different views and therefore, lay a solid foundation for future L2 vocabulary learning studies. However, some limitations in them warrant further researches on the issue. Most of the early studies mainly focusing on task type and learning strategies, have confirmed the correctness of input-output hypothesis and the involvement load hypothesis, but remained many issues to resolved. Given the limitations in the previous research, this study is a continuation and is a subject designed with different learning tasks as the independent variables and L2 the vocabulary acquisition as the dependent variables.

3. Methodology

This chapter reports the research design of the present study in order to answer the three research question. The data examined in the present study came from prior vocabulary tests, including receptive vocabulary test, productive vocabulary test and different tasks.

3.1 Research Questions

The present study intends to investigate the effect of vocabulary learning tasks on vocabulary acquisition, measured by a modified version of Vocabulary Knowledge Scale. Specifically, it addresses the research question:

Does vocabulary learning task have a significant effect on EFL’s vocabulary acquisition ?

3.2 Research Design

3.2.1 Subject

The subjects in this study were 75 second-year non-English majors from two classes at Nanjing Tech University, among whom 20 participants majored in Business Administration, 20 in Communications Engineering, and 35 in Pharmacy. All the participants in the present study were all native speakers of Chinese who had learned English for around eight years, being considered as intermediate EFL learners and agreed to be cooperative as well as follow the instructions.

To answer the research question, those participants were randomly assigned to one of the three groups of equal size. They were required to read the same three sets of sentences, each of which contained 6 sentences. Then they completed separate target word-based tasks, followed by one test of L2 vocabulary acquisition. If they could write correctly, they would get 2 points, otherwise they would get 1 point. The higher their score was, the better their vocabulary acquisition was.

The target words were given their meanings and grammatical functions in two ways. One way was to present the meaning and grammatical function of each target word in the brackets after the sentence where it appeared. The other way was to provide participants with a mini-dictionary, where target words were included. They had to consult each target word in the dictionary for sentence understanding and target word-based exercises The former was input hypothesis, considered as low involvement load while the other was different. Table 3.1 is a part of the research design.

Table 3.1 Design: Task types and input-output hypothesis by group

Form the above table ,we can clearly know the three group’s target types and the three EFL vocabulary acquisition tasks were related to sentence reading. Each target word appeared in one sentence, so 18 sentences were written. In the instructions of sentence reading for Group 1, each target word was highlighted in bold print and was glossed in the brackets after the sentence, involving the Chinese translation and part of speech and inflection. Students in the first group were designed to do meaning matching task, where one target word matched with its meaning. Students in the second were required to connect sentences, where they could consult to a dictionary in order to get the target words’ proper meaning. Students in the third group needed to write target words, which means they had to write the correct words depending on their definition after reding the 18 sentences.

The dependent variable was participants’ vocabulary acquisition. It was ope-rationalized as consisting of receptive and productive vocabulary knowledge, and measured by the vocabulary knowledge scale (see also the Vocabulary knowledge scale subsection).

In this design, time on task was controlled in 25 or 20 minutes, since it was a dependent variable, which might affect the relationship between task-induced involvement and L2 vocabulary acquisition. So it was necessary to control time.

3.2 .2 Target words

Target words were operationalized as words unknown to all the participants in this study. Basically, there are four ways. The first way is to do a pilot study by randomly selecting some EFL learners who are at the same EFL level as those in the study and testing them to see whether they do not know some words. The second way is to select some words which are deemed as unfamiliar to the participants in the study and ask the participants to make unfamiliarity judgments while they are performing L2 vocabulary learning tasks. The third way is to use pseudo words as target words in order to ensure that no participant knows them. The last way is to administer a test of L2 vocabulary size before the participants participate in the experiment and select words that none of them knows. The first way cannot guarantee some target words are unknown to all the participants. In the second way, participants’ unfamiliarity judgments may be subjective, influenced by L2 vocabulary learning tasks. Moreover, a target word will be invalid as long as one participant judges it as familiar. One problem with the third way is that the use of pseudo words may be unethical, for participants may feel fooled by being asked to devote their time and energy to learn some meaningless words (pseudo words). This study preferred the fourth way, whose proper use can guarantee the unfamiliarity acquisition to participants.

Words familiarity seems to play an important role in SLVA. It is necessary to analyze how background knowledge exerts influence on L2 vocabulary acquisition, such as the acquisition of word form and word meaning. Topic familiarity is helpful in acquiring L2 word meaning. Some researches have shown that it is harder to learn a word for a new concept than a word which is simply a new label for a familiar concept (Nagy, et al., 1987; Sheffelbine, 1990). Nagy (1997) claims that adult L2 learners may possess substantial knowledge not available to younger first-language. Diakidoy’s research (1993) finds that participants’ familiarity with the passage have a significant effect on learning word meanings. Based on this, Pulido (2004) points out that in most cases of learning L2 word meaning, it involves mapping new lexical forms to familiar meanings or concepts already in the existing semantic or conceptual system. Parry's study (1997) illustrates that the participant's success of acquiring L2 word meaning results greatly from texts on a topic in which he had rich and extensive knowledge and is familiar with the topic.

As far as the topic familiarity in acquiring word form is concerned, Pulido has given some insightful findings to the issue. According to Pulido's study (2004), the relationship between passage comprehension and word form recognition (intake) was inconsistent when the participants’ background knowledge was taken into account at the same time, which suggested a rather complex role of topic familiarity in acquiring word form. Many researchers have proposed their frameworks of vocabulary knowledge for assessment purpose, among which there is a main approach to classify vocabulary knowledge---the developmental approach. According to Read (1997, p. 315), the developmental approach identifies “levels of knowledge that may be interpreted as stages in the acquisition of the word”. Some first language vocabulary researchers have proposed scales to represent the varying degrees of knowledge.

L2 vocabulary acquisition was ope-rationalized as receptive and productive knowledge, measured by the modified Vocabulary Knowledge Scale (VKS). The VKS was originally designed by Paribakht and Wesche (2001). According to Paribakht and Wesche (2001, p. 179), “VKS uses a 5-point scale combining self-report and performance items to elicit self-perceived and demonstrated knowledge of specific words in written form. The scale ratings range from total unfamiliarity, through recognition of the word and some idea of its meaning, to the ability to use the word with grammatical and semantic accuracy in a sentence.” A few scales have also been developed for use with second language learners. For instance, Paribakht and Wesche (1993) produce the Vocabulary Knowledge Scale (VKS). This study used Min’s (2008) modified 4-item VKS. The test format with possible responses given is shown as follows (See see Appendix II ):

1. I have never seen this word.

2. I have seen this word before, but I don't know what it means.

3. I have seen this word before, and I think it means _______ (synonym or translation).

4. I know this word. It means ______ (synonym or translation).

5. I can use this word in a sentence.

The test of L2 vocabulary acquisition was administered twice, but the presentation order of the target words was altered in order to prevent potential order effects.

3.2 .3 Testing L2 vocabulary acquisition

The test of L2 vocabulary size used to select the 18 target words was one adapted from the Vocabulary Size Test, created by Paul Nation, Victoria University of Wellington, and found at http://www.lextutor.ca/. And it was measured by the modified Vocabulary Knowledge Scale. According to Paribakht and Wesche (2001, p. 179), “VKS uses a 5-point scale combining self-report and performance items to elicit self-perceived and demonstrated knowledge of specific words in written form. The scale ratings range from total unfamiliarity, through recognition of the word and some idea of its meaning, to the ability to use the word with grammatical and semantic accuracy in a sentence.” After special practice, the participants attended a vocabulary acquisition test of target words, in which the 18 target words were mixed in it in order to find whether the participants had acquired them or not. The test time is 25 minutes. The acquisition of each target word has 4 ranks: (1) not knowing the word; (2) knowing the word but having no access to its word meaning; (3) knowing the word and its meaning; (4) having the ability of making proper sentence with the word. According to different rank, there are related standards of grading. In this study, vocabulary acquisition refers to ranks 3 and 4, and if they can write correctly the target words, they will get 2 points, otherwise one point. So, the score rang in this study is from 18 to 36.

3.3 Data collection and analysis

75 second-year non-English majors from two classes at Nanjing Tech University participant-ed in the present study and were divided into three groups randomly to complete input task and output task respectively. Before the test, students were asked to complete a questionnaire about their gender, age, major, residence and the vocabulary acquisition. Then, they were required to read three sets sentences. Each set includes 6 sentences. After that, they began to do different tasks as required in their groups. As soon as the participants completed the tasks, the papers were collected.

A statistical analysis of the collected data was conducted by SPSS 13.0. One-way ANOVA were conducted to answer the research question.

4.Results and Discussion

Chapter Four is divided into two major parts. The first part deals with the results of the present study , the second part discusses the main findings.

4.1 Results

The descriptive statistics for the effect of the L2 vocabulary learning tasks on vocabulary acquisition were displayed in Table 4.1. As mentioned in Chapter Three, the research question addressed whether vocabulary learning tasks affected EFL learner's vocabulary acquisition, i.e., EFL learner’s initial knowledge of target words.

In order to tackle the research question, the data collected were analyzed using SPSS version 13.0. The alpha level was set at .05. As a result, one-way ANOVA was conducted to analyze the results in order to address the research question.

Table 4.1 Descriptive statistics for the immediate test

Table 4.1 is for descriptive statistics, including the category, sample size, mean, standard deviation, and standard error of average, the average 95% confidence interval, the maximum and the minimum, in which we can see that there are obvious change from 1 to 3groups. From the mean, we can see clearly that the results of the three tasks are different. For example, in task1 of imme1, there are 25 samples and mean number of vocabulary acquisition in the input task was 22.60 while the mean number of vocabulary acquisition in the output task was 25.28 and 27.44. As it states, the mean differences is big, so the descriptive statistics indicated that vocabulary learning tasks have a significant effect on vocabulary acquisition. This result illustrates the input-output hypothesis concerning L2 receptive vocabulary knowledge acquisition as task1 ( meaning match) and task2 ( connecting sentences ) refers to input, task3 (writing target words) in this table. The present finding supports Swain’s (1993) argument that output activity induces L2 learners to reflect on the language form and this makes acquisition more likely to occur.

Table4.2 ANOVA

According to table 4.2, F=5.88 p= .004 lt; .01 it means that between the three different tasks, at least two tasks exist statistically significance. Maybe there is significant effect on L2 language learner’s vocabulary acquisition between task one and task two. Maybe there is significant effect on L2 language learner’s vocabulary acquisition between task one and task three. Also, there is probably significant effect on L2 language learner’s vocabulary acquisition between task two and task three. So,we need to do a multiple comparisons to assure which two group have effect on EFL’s vocabulary acquisition. The result is displayed in table 4.3.

Table 4.3 Multiple Comparisons

*.The mean difference is significant at the .05 level.

Table 4.3 is the multiple comparisons. It indicates that there exists significant difference between task1 and task3( p=.004 lt; .05) and there isn’t significant differences between task1 and task2, since p=.17 gt; .05 in those two tasks. Also, for the reason, p= .32 gt; .05, there is no significant difference between task2 and task3. It seems reasonable that output oriented task allows for deeper processing of target words by helping L2 learners establish strong meaning-form connections through deeper processing of target words. The results showed that output tasks are much more useful to acquire L2 vocabulary than input tasks. In other words, it seemed to verify the hypothesis: there is main effect of vocabulary learning task type on vocabulary acquisition.

4.2 Discussion

The focus of this study was on the relative effectiveness of learning task and involvement load. We have drown several conclusions. Firstly, vocabulary learning tasks have a significant main effect on vocabulary acquisition. Secondly, involvement load has no significant effect on the vocabulary acquisition. Finally, there is no significant interaction between vocabulary learning tasks and involvement load on vocabulary acquisition.

This study found that output orientation of a task performed better input orientation of a task on SLVA. One plausible explanation for the stronger effect of output-oriented tasks is L2 learners’ more attention to form. This explanation is in conformity with Toth’s (2006) argument that L2 learners’ internal language processing engaged in during the output-oriented tasks may produce greater benefits for learning than during the input-oriented tasks, and Izumi’s (2002) statement that output-oriented tasks may facilitate L2 vocabulary development by forcing L2 learners to notice L2 forms. Another explanation is task demand. Output-oriented tasks involve both input processing and production, where L2 learners have to respond by encoding the meanings of L2 forms, whereas input-oriented tasks involve only input processing, where L2 learners have to respond to input by signaling the meanings of L2 forms, so the processing of L2 forms in output-oriented tasks goes deeper.

According to Hulstijn and Laufer (2001), higher involvement load induced by the task would result in better retention, regardless of whether it is an input task or an output task. However, this claim, suggested by the involvement load hypothesis, was not verified by this study. Also the lack of interaction between task type and involvement load is limited to the present definitions, it remains unknown whether task type and involvement load would still fail to interact with each other if each of them or one of them were classified into more than two levels.

This study attempted to provide insights for the way that the input-output hypothesis was related to the involvement load hypothesis in contributing to our understanding of L2 vocabulary acquisition. The input-output hypothesis was partly supported while the involvement load hypothesis was rejected. A significant conclusion drawn from this study was that the involvement load hypothesis may not the only determining factor in task effectiveness, task type, i.e. input and output orientation of word-focused task may be a determining factor. This finding indicates that Laufer and Hulstijn’s (2001) proposal still has a long way to go before it achieves its full potential.

5.Conclusions

请支付后下载全文，论文总字数：45871字