Productive Vocabulary Development In Chinese L2 Learners' Writing: A Corpus-Based Study

Writing, as one of the four basic skills of L2 learning, has always occupies an important position in language teaching and learning. However, many sampling surveys of L2 teaching and learning indicate that Chinese L2 learners have not learned to write effectively in L2. One of the causes is short of adequate vocabulary. Various methods have been used to measure learners' productive vocabulary in previous research. Among them, the Lexical Frequency Profile (LFP) is a better one. In China, the research based on Chinese L2 learner corpora (LCs) is just in the beginning stage. However, since the appearance of Chinese Learner English Corpus (CLEC) and Spoken and Written English Corpus of Chinese Learners (SWECCL), quite a lot of researchers have used them to investigate Chinese learners' interlanguage. From literature review, it is noticed that very few studies based on Chinese L2 LCs have utilized the method of LFP to measure the vocabulary development in Chinese L2 learners' writing from the angle of different grades. This thesis aims to fill this gap by trying to providing an objective picture of productive vocabulary development in Chinese L2 learners' writing.To achieve the above aim, 60 argumentative essays and 60 narrative essays from Year 1 to Year 3 are chosen from Written English Corpus of Chinese Learners (WECCL) as the samples.The research questions are:1. What are the LFPs of Chinese L2 learners in the argumentative and narrative essays from Year 1 to Year 3? How do the LFPs develop from Year 1 to Year 3 in the two types of writing?2. In the two types of writing are there any significant differences concerning the LFPs among the three years?3. In each of the three years are there any significant differences concerning the LFPs between argumentative and narrative essays?In order to answer the first research question, all the chosen samples are input to SPSS for descriptive statistics analysis. Concerning the second research question, a post hoc analysis of the ANOVA (using Tukey procedure) is applied to observe the differences. To answer the third research question, the means of tokens in the both writing styles from Year 1 to Year 3 are input into SPSS to compare them with the help of Independent-Samples t-Test.After the data processing, the following findings are acquired:1. Generally speaking, the students of Year 1 make least use of beyond 2000 words and rely most on the basic 2000 words. There is a tendency for the students to use more beyond 2000 words with the growth of grades. Although the mean of tokens beyond 2000 has grown considerably in each year, the growth is not the same in different types of writing. In 2nd year, the tokens have increased 7.5 on the average in argumentation, 5.8 in narration. In Year 3, the tokens have increased 5.1 and 2.8 respectively. It seems that the L2 learners are inclined to use more beyond 2000 words in argumentative compositions than in narrative compositions when required to write.2. After post hoc analysis of the ANOVA (using Tukey procedure), it is found that the means of tokens between Year 1 and Year 2 and between Year 1 and Year 3 have significant difference. No such difference has been found between Year 2 and Year 3. It is testified that the discrepancy of the token's growth between each year has statistically significant difference. The current study confirms that the vocabulary 'plateau' does exist in Chinese L2 learners, and it appears at the period from Year 2 to Year 3.3. Through the Independent-Samples t-Test, it is verified that the LFPs in each year between argumentative and narrative essays are significantly different. The conclusion is that the vocabulary chosen by the L2 learners in writing is varied with the shift of writing topics or styles.This research may provide certain pedagogical implications like:1. Since the vocabulary used by students is varied significantly with the shift of writing topics or styles, in writing course, time should be spared to different writing styles to help L2 learners use more infrequent words.2. When grading compositions, besides correctness, more rewards should be given to lexical richness to encourage students to use less frequent words and newly-learned words.3. In addition, output-oriented approaches should be paid more attention to in order to enlarge L2 learners' productive vocabulary.4. Corpus-based analyses have led to a new inductive teaching methodology, called data-driven learning (DDL). It has been approved that DDL is helpful to develop learners' autonomous learning habit and improve their learning achievement. So DDL is worthwhile being applied when possible.5. In the four years of academic learning in college, the first two years is the key period. Therefore, in grade two, it is necessary to keep cautious to the fossilization of L2 and utilize all possible resources to aid the learners to go beyond the plateau and to reach a new climax in the following academic years.